铁电随机存取存储器 (F-RAM)及设备系统设计
<p><span style="color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> <span style="font-size:16px;"> 对于为消费类、工业和其他细分市场设计的电池供电移动设备而言，可靠的长期数据存储已成为日益重要的需求。在早期的产品中，使用的是常规的非易失性存储器 (NVM) 技术，例如闪存或电可擦除可编程只读存储器 (EEPROM)，来满足这种需求。</span></span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" /><span style="font-size:16px;"><span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"> 然而，对于当今的先进移动产品，用户不断期望更长的电池寿命，这使得能够提供可靠存储而又不影响设计性能或功耗预算的选择大大受限。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">本文介绍 Cypress Semiconductor 的 Excelon 铁电随机存取存储器 (F-RAM) 系列，并展示了如何使用该存储器来满足电池供电设备对可靠的长期存储的需求。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<strong style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">便携式设备面临的存储挑战</strong><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"> 在可穿戴设备、物联网设备和其他便携式产品的设计中，产品功能的增强直接伴随着对大型非易失性存储的需求。用户对更全面信息的需求促使这些设计中集成了更多类型的传感器，而这些传感器以更高的分辨率和更快的更新速率运行。同时，用户希望这些先进的产品能够提供全面的历史数据和趋势视图，而不仅限于当前传感器数据的简单快照。特别是，该设备必须能够按需生成此数据目录，而无需主动连接到云、智能手机或其他外部设备。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"> 设计人员试图用传统的 NVM 技术来满足这些基本要求，但却面临多重困难，尤其是在功耗受限的设计中。由于完成编程过程所需的周期较长，因此许多 NVM 技术的写入时间本身就比 RAM 要慢得多。传统的 EEPROM 可能具有几毫秒的写入时间。即使在高级闪存中，由于在写入周期内需要额外的“停留时间”，也会降低性能。反过来，更长的写入周期意味着总体电流消耗增加，以及数据更新速率降低。最后，传统 NVM 器件的写入寿命规格通常有限。如果以常规数据存储所需的重复写入周期使用，则这些器件可能会在产品的使用寿命内失效。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">面向越来越多的电池供电设计，F-RAM NVM 器件提供了一种更简单的长期存储解决方案，兼具所需的速度、耐用性和低功耗运行优势。典型 F-RAM 器件的写入耐久性和写入周期时间优于 EEPROM 和闪存好几个数量级，甚至在速度上接近静态 RAM (SRAM)。实际上，F-RAM 兼具传统 RAM 的性能优势和其他 NVM 技术的非易失性存储功能。在 F-RAM 解决方案中，Cypress Semiconductor 的 Excelon LP（低功耗）F-FRAM 系列更进一步，能够满足电池供电的可穿戴设备和其他移动产品对超低功耗的基本要求。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<strong style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">超低功耗 F-RAM</strong><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"> Cypress 的 Excelon LP F-RAM 器件是集成的非易失性存储器子系统，结合了 F-FRAM 阵列、寄存器、控制和接口逻辑，以及一个特殊扇区，其设计用于在多达三个标准回流焊周期中保存内容（图 1）。</span></span></p>
<div align="left" style="overflow-wrap: break-word; margin: 16px 0px; padding: 0px; box-sizing: border-box; line-height: 28px; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;"><span style="font-size:16px;"><img alt="" border="0" class="zoom" height="388" id="aimg_sbbB8" onclick="zoom(this, this.src, 0, 0, 0)" src="https://www.digikey.cn/-/media/Images/Article%20Library/TechZone%20Articles/2019/December/Use%20an%20F-RAM%20to%20Build%20Battery-Powered%20Devices/article-2019-use-to-f-ram-fig1.jpg?ts=82983d44-244f-454a-aff7-74cdc1ca1aa5&la=zh-CN-RMB" style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; border: none; vertical-align: middle; cursor: pointer; display: block; max-width: 100%;" width="600" /><i style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">图 1：Cypress Semiconductor 的 Excelon LP F-RAM 器件集成了 F-RAM 阵列和支持电路，以提供可通过标准 SPI 端口访问的完整存储器子系统。（图片来源：Cypress Semiconductor）</i></span></div>
<p><span style="font-size:16px;"><span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">Excelon LP F-FRAM 器件提供的长期可靠性水平远远超过典型的 EEPROM 或闪存。这些器件具有 1015 个读/写周期的使用寿命和 151 年的数据保留能力，超过了任何实用性可穿戴设备或物联网设备的实际使用寿命。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">这些器件的写入性能还提高了应用的整体可靠性。由于这些器件以总线速度将数据写入非易失性 F-RAM 阵列，因此与其他类型的 NVM 器件相比，大幅降低了丢失数据的几率。在那些器件中，不仅写入时间要长得多，相应的内部数据缓存需求还造成较宽的易损窗口，如果在写入序列完成之前出现电源故障，数据可能会丢失。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">与其他 NVM 技术不同，Excelon LP F-FRAM 器件以极低的电流电平运行，而这正是延长便携式产品的电池寿命所需要的。Cypress 的 CY15x108QI 8 兆位 (Mb) F-RAM LP 系列运行在 20 兆赫 (MHz) 时，仅消耗 1.3 毫安 (mA) 电流，而 Cypress 的 CY15x104QI 4 Mb F-RAM LP 系列仅消耗 1.2 mA 电流。这些器件还为开发人员提供了多种选择，以实现进一步降低电流消耗，具体如下所述。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">Excelon LP 系列产品设计用于支持广泛的系统要求，可在商业和工业温度范围内以及不同的供电电压下使用。例如，4 Mb CY15V104QI 和 8 Mb CY15V108QI 的供电电压范围为 1.71 V 至 1.89 V，而 4 Mb CY15B104QI 和 8 Mb CY15B108QI 的设计工作电压范围为 1.8 V 至 3.6 V。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<strong style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">简单的系统设计</strong><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">除了确保与不同应用的运行要求适当匹配之外，这些器件还可简化系统设计。在典型的设计中，开发人员将使用串行外设接口 (SPI) 总线将一个或多个 Excelon LP F-RAM 器件作为 SPI 从设备连接到 SPI 主设备，例如微控制器（图 2）。</span></span></p>
<div align="left" style="overflow-wrap: break-word; margin: 16px 0px; padding: 0px; box-sizing: border-box; line-height: 28px; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;"><span style="font-size:16px;"><img alt="" border="0" class="zoom" height="301" id="aimg_B4wXW" onclick="zoom(this, this.src, 0, 0, 0)" src="https://www.digikey.cn/-/media/Images/Article%20Library/TechZone%20Articles/2019/December/Use%20an%20F-RAM%20to%20Build%20Battery-Powered%20Devices/article-2019-use-to-f-ram-fig2.jpg?ts=3b185336-6a97-4d93-a178-48b117832eeb&la=zh-CN-RMB" style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; border: none; vertical-align: middle; cursor: pointer; display: block; max-width: 100%;" width="500" /><i style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">图 2：开发人员只需将一个或多个 Cypress Semiconductor 的 Excelon LP F-RAM 器件连接至由 SPI 主设备（如微控制器）控制的 SPI 总线，即可在其设计中添加长期存储。（图片来源：Cypress Semiconductor）</i></span></div>
<p><span style="font-size:16px;"><span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">互连 SPI 总线上的事务简单而快速。写入存储器时，Excelon LP F-RAM 器件没有前述闪存或 EEPROM 技术的额外写入延迟。相反，当每个字节通过 SPI 总线到达器件时，会被立即写入 F-RAM 阵列，从而大幅降低由于突然断电而导致数据丢失的风险。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">对于系统开发人员而言，写入过程遵循简单的 SPI 协议，其中涉及工业标准 SPI 操作代码（操作码）。主机处理器通过发送写使能 (WREN) 操作码 (06h) 同时升高然后降低片选 (ØCS) 线的电平，来开始每个写入序列。在短暂的初始化阶段之后，主机处理器通过依次发送写操作码 (02h) 和 24 位地址来开始写入操作。（在这些器件中，该地址的高四位会被忽略，但可确保与将来更高密度的 F-RAM 器件兼容。）发送地址后，主机处理器即会开始传输数据字节（图 3）。</span></span></p>
<div align="left" style="overflow-wrap: break-word; margin: 16px 0px; padding: 0px; box-sizing: border-box; line-height: 28px; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;"><span style="font-size:16px;"><img alt="" border="0" class="zoom" height="163" id="aimg_d25XF" onclick="zoom(this, this.src, 0, 0, 0)" src="https://www.digikey.cn/-/media/Images/Article%20Library/TechZone%20Articles/2019/December/Use%20an%20F-RAM%20to%20Build%20Battery-Powered%20Devices/article-2019-use-to-f-ram-fig3.jpg?ts=a4c380bc-f14b-4c55-8080-dbc0bbb0c3bd&la=zh-CN-RMB" style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; border: none; vertical-align: middle; cursor: pointer; display: block; max-width: 100%;" width="600" /><i style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">图 3：在标准 SPI 写入序列期间，Cypress Semiconductor 的 Excelon LP F-RAM 器件会立即将数据写入 F-RAM 阵列，而不存在与早期 NVM 技术相关的任何缓冲或停留时间延迟。（图片来源：Cypress Semiconductor）</i></span></div>
<p><span style="font-size:16px;"><span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">当主机处理器发送数据字节时，只要主机处理器将 ØCS 线保持低电平并继续发送时钟信号，F-RAM 器件就会在内部自动递增地址。因此，设计人员可以在需要任意单字节写入和块写入组合的设计中使用 Excelon LP F-RAM 器件。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">读取操作遵循类似的 SPI 协议。降低 ØCS 电平后，主机处理器会发送读取操作码 (03h) 和 24 位地址。Excelon LP F-RAM 器件通过每个 SCK 时钟周期在 SO 线上传输数据字节来立即做出响应。与写入操作一样，只要主机处理器将 ØCS 保持低电平并继续发出 SCK 时钟，读取操作就会继续。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<strong style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">延长电池寿命</strong><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">除了简单的系统设计要求，这些低功耗 F-RAM 还为开发人员提供了减少电流消耗和延长电池寿命的选择。Cypress 的 CY15x10xQI 器件专为电池供电应用而设计，其集成了内置的涌流控制电路，可减少 NVM 器件上电时通常会产生的相对较大的电流。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">在使用传感器来跟踪进展相对缓慢的现实事件的可穿戴设备和物联网设计中，Cypress 的 Excelon LP F-RAM 器件还允许开发人员采用不同的策略来延长其电池寿命。在这些设计中，Cypress 的 Excelon LP F-RAM 器件通常可以在较低的时钟频率下运行，从而降低电流消耗。例如，以 1 MHz 时钟运行时，8 Mb CY15V108QI 的电流消耗会从 20 MHz 时的 1.3 mA 降至 300 µA。同样，4 Mb CY15V104QI 在 1 MHz 时仅需要 200 µA，而在 20 MHz 时则需要 1.2 mA。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">使用 Excelon LP F-RAM 器件提供的特殊低功耗模式，开发人员可进一步降低可穿戴设备和物联网应用中经常出现的各种空闲时段内的系统功耗。这些 F-RAM 器件支持三种功耗降低模式，允许开发人员以响应时间为代价来降低电流消耗。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">每当提高 ØCS 电平以终止 SPI 序列时，这些器件就会自动进入第一个低功耗模式，即待机模式。相反，在降低 ØCS 电平以开始新的 SPI 序列时，器件会自动退出待机模式。在待机模式下，8 Mb CY15V108QI Excelon LP F-RAM 仅消耗 3.5 µA，而 4 Mb CY15V104QI 仅消耗 2.3 µA。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">待机模式可立即自动减小电流，并且无需施加额外的延迟便可返回正常工作模式。但对于空闲时间较长的应用，即使是这种水平的电流消耗，长远来看也会不必要地缩短电池寿命。针对这些情况，Excelon LP F-RAM 器件提供了其他两种低功耗模式：深度省电模式和休眠模式。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">与默认的待机模式不同，深度省电和休眠模式通过使用特殊的 SPI 操作码以显式方式进入。类似于读写 SPI 操作，SPI 主设备会发出深度省电 (DPD) 操作码 (BAh) 或休眠 (HBN) 操作码 (B9h)，以命令 F-RAM 器件进入相应的低功耗模式（图 4）。</span></span></p>
<div align="left" style="overflow-wrap: break-word; margin: 16px 0px; padding: 0px; box-sizing: border-box; line-height: 28px; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;"><span style="font-size:16px;"><img alt="" border="0" class="zoom" height="208" id="aimg_T5X8j" onclick="zoom(this, this.src, 0, 0, 0)" src="https://www.digikey.cn/-/media/Images/Article%20Library/TechZone%20Articles/2019/December/Use%20an%20F-RAM%20to%20Build%20Battery-Powered%20Devices/article-2019-use-to-f-ram-fig4.jpg?ts=6e4b5925-3ec5-4c6c-9550-00e2db16ca83&la=zh-CN-RMB" style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; border: none; vertical-align: middle; cursor: pointer; display: block; max-width: 100%;" width="600" /><i style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">图 4：开发人员可以使用标准 SPI 协议将 Cypress Semiconductor 的 Excelon LP F-RAM 器件置于深度省电 (DPD) 或休眠模式 (HIB)，这些模式会大幅降低电流消耗，但会导致进入 (tENTxxx) 和退出 (tEXTxxx) 相应的低功耗模式时产生不同的延迟。（图片来源：Cypress Semiconductor）</i></span></div>
<p><span style="font-size:16px;"><span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">这些低功耗模式的效应非常明显，使电流消耗降至 1 µA 以下（表 1）。尽管可大幅降低器件电流，但使用这些模式却需要在可能影响时间敏感型数据的操作方面做出让步。基于操作码的 DPD 和 HIB 低功耗模式会带来额外的延迟，这与进入模式所需的时间（tENTDPD 或 tENTHIB）以及退出模式所需的时间（tEXTDPD 或 tEXTHIB）有关（表 1 和图 4）。</span></span></p>
<table cellspacing="0" class="t_table" style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; empty-cells: show; border-collapse: collapse; border-spacing: 0px; background-color: rgb(255, 255, 255); border: 1px solid rgb(227, 237, 245); color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">
<tbody style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">
<tr style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;"> </span>
<table cellspacing="0" class="t_table" style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; empty-cells: show; border-collapse: collapse; border-spacing: 0px; background-color: transparent; border: 1px solid rgb(227, 237, 245);">
<tbody style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">
<tr style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">器件</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">活动模式电流</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">待机模式电流</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">深度省电 (DPD) 模式电流和延迟</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">休眠 (HIB) 模式电流和延迟</span></td>
</tr>
<tr style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">CY15V104QI</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">1.2 mA (20 MHz)<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
200 μA (1 MHz)</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">2.3 μA (25°C)</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">0.7 μA (25°C)<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tENTDPD：3 μs<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tEXTDPD：150 μs</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">0.1 μA (25°C)<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tENTHIB：3 μs<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tEXTHIB：5 μs</span></td>
</tr>
<tr style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;">
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">CY15V108QI</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">1.3 mA (20 MHz)<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
300 μA (1 MHz)</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">3.5 μA (25°C)</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">0.9 μA (25°C)<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tENTDPD：3 μs<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tEXTDPD：240 μs</span></td>
<td style="overflow-wrap: break-word; margin: 0px; padding: 4px; box-sizing: border-box; border: 1px solid rgb(227, 237, 245); overflow: hidden;"><span style="font-size:16px;">0.1 μA (25°C)<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tENTHIB：3 μs<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box;" />
tEXTHIB：5 μs</span></td>
</tr>
</tbody>
</table>
<span style="font-size:16px;"> </span></td>
</tr>
</tbody>
</table>
<p><span style="font-size:16px;"><i style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">表 1：Excelon LP F-RAM 功耗模式下的电流消耗以及进入（tENTDPD 或 tENTHIB）或退出（tEXTDPD 或 tEXTHIB）基于操作码的深度省电和休眠模式的相关延迟。这些数值为商用低压版本的数据，供电范围为 1.71 V 至 1.89 V，工作温度范围为 0°C 至 +70°C。（数据来源：Cypress Excelon LP F-RAM 规格书）</i><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">在使用基于操作码的低功耗模式时，开发人员需要在这些模式下电流消耗降低的好处与进入和退出这些模式所需的电流消耗和时间之间取得平衡。任何空闲时段较长的系统都可能是这两种模式的候选应用，但是特定的模式选择关键取决于活动时段内 F-RAM 器件运行的预期占空比。对于需要以高占空比运行的 F-RAM 器件，反复进入和退出低功耗模式的代价可能适得其反。例如，Cypress 建议，任何空闲时段为 10 秒或更长时间的应用都非常适合使用休眠模式。</span><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<strong style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">总结</strong><br style="overflow-wrap: break-word; margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(50, 50, 50); font-family: myFont, "Microsoft YaHei"; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;" />
<span style="color: rgb(50, 50, 50); text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: myFont,"Microsoft YaHei"; font-style: normal; font-weight: 400; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; widows: 2; float: none; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">电池供电的可穿戴设备和物联网设备对长期数据存储的新兴需求，迫使开发人员不得不寻找功耗低，而且没有与 EEPROM 和闪存等传统 NVM 技术相关的性能限制的 NVM 器件。Cypress Semiconductor 的 Excelon 低功耗 (LP) F-RAM 器件基于 F-RAM 技术固有的速度和可靠性优势构建，并将其固有的低电流需求与可编程的低功耗模式相结合，可将电流消耗降至不到 1 微安。使用 Cypress 的 Excelon LP F-FRAM，开发人员可以为电池供电的设计快速补充长期数据存储，这些存储具有传统随机存取存储器的速度，并且能够可靠地保留数据超过 150 年。</span></span></p>
<p>铁电是个好东西，成本不那么敏感的地方这东西可以节省大量开发成本和时间。</p>
<p>铁电贵呀，MRAM便宜</p>
18566202629 发表于 2024-1-2 15:20
铁电贵呀，MRAM便宜
<p>国产铁电性价比好很多</p>
18566202629 发表于 2024-1-2 15:20
铁电贵呀，MRAM便宜
<p>国产铁电，有很好的性价比，对比富士通和英飞凌（赛普拉斯）</p>
页:
[1]