探究适配器中的ID芯片

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探究适配器中的ID芯片 [复制链接]

昨天关于MSP430替代适配器中ID芯片的内容引起了大家的兴趣(https://bbs.eeworld.com.cn/thread-430806-1-1.html)，我也做了一点更深入的研究。从网上找到的图片DS2501（http://datasheets.maximintegrated.com/en/ds/DS2502.pdf）




这个就是一个非易失的存储器EPROM。
好的在dell的适配器里，这个存储器到底存了那些东西呢？这是来自美国的一个实际的读出数据：

002100: 11 36 14 6D 02 00 00 B8    .6.m.... = ROM
002108: F3 FF FF FF FF FF FF 00    ........ = STATUS
002110: C3 FF FF FF FF FF FF FF   ........ = STATUS CRC (=C3)
002118: 44 45 4C 4C 30 30 41 43    DELL00AC = Start of page 0
002120: 30 39 30 31 39 35 30 34    09019504
002128: 36 43 4E 30 43 38 30 32    6CN0C802
002130: 33 34 38 36 36 31 36 31    34866161 = End of page 0
002138: 52 32 33 48 38 41 30 33    R23H8A03 = Start of page 1
002140: 4D 7C FF FF FF FF FF FF    M|......

002148: FF FF FF FF FF FF FF FF    ........

002150: FF FF FF FF FF FF FF FF    ........ = End of page 1
002158: FF FF FF FF FF FF FF FF    ........


The first byte is the code protection bits (bits 0-3) and memory usage map (bits 4-7, reserved
for TMEX) the next 4 are page redirection bytes, bytes 6 and 7 are maintained clear/unprogrammed and byte 8 is programmed to 00 at the
factory. C3 is the CRC computed by the DS2501, this was checked by using the program I wrote in windows for computing the CRC
(x^8+x^5+x^4+1), and was determined to be valid. The next five lines are the actual data space information. Dell is the manufacturer, 0 is
a field identifier, AC is the type of adapter, 090 is the wattage rating  (my thought is that it allows for 99+ watt power adapters),
195046 is the nominal voltage rating (19.5 Volts) followed by thenominal current rating adjusted to one decimal place (4.6 Amps). From
C to H8 is the barcode number of the power adapter and A03 is the revision of the power adapter. 4D7C is an end of information identifier as I have found this on another adapter I own.