关于写C554的寄存器FCR的问题

wujieflash

关于写C554的寄存器FCR的问题 [复制链接]

诸如 LCR DLL DLH IER等寄存器,我都能写进去,再读出来,可FCR就是不行,
我把代码写在下面,哪位兄弟姐妹指导一下
//定义相关宏
#define UART_BASE_ADDR            (0x20300000

#define C554_CH1_FCR                   (UART_BASE_ADDR+4)

#ifndef C554_REG_READ
#define C554_REG_READ(C554_reg, result) \
    result = \
        (*(volatile unsigned short  *)(C554_reg)) #endif


#ifndef C554_REG_WRITE
#define C554_REG_WRITE(C554_reg, data) \
    (*(volatile unsigned short  *)(C554_reg)) = \
        (data)
#endif


//写FCR寄存器
C554_REG_WRITE(C554_CH1_FCR, 0,0x1);// FCR0置1

C554_REG_WRITE(C554_CH1_FCR, 0,0x8f);// 向FCR寄存器写值

cyllouis

C554_REG_WRITE(C554_reg, data)

C554_REG_WRITE(C554_CH1_FCR, 0,0x1);// FCR0置1
C554_REG_WRITE(C554_CH1_FCR, 0,0x8f);// 向FCR寄存器写值

仔细看了一下,好像你没用对,多了一个参数

rcsun

我修改了,不是这个问题

yy0216

FCR and ISR share the same address space in the UART regsiter set (0x02). The FCR is a write only register and the ISR is a read only register. When you do a write to address 0x02 you write to the FCR register, but when you do a read of address 0x02 you would read the ISR register and not the FCR register.

To overcome this problem you would have to save the FCR value to a variable before you write to the FCR register. And when you want to know what value is in the FCR register, you would read this value from the variable