嗨，伙计们，
我有一个奇怪的问题，这使我发疯了！
我已经创建了一个函数，它能够读取包含16位子地址的I2C。
在我的情况，我需要回读4个字节的子地址，第四字节的值将一个值0，1或2。
如果（睡眠计数器和GT；50）{
睡眠计数器＝0；
readdata = i2c_1_dsp_master_read（device_addr_ic_1，mod_audio_detect_detect_reg_readbackalgsigma2001_addr，4）；
如果（Read DATA＝2）{
[做某事]
否则，（Read DATA＝＝1）{
[做某事]
否则，（Read DATA＝＝0）{
做某事
}
}
其中读取函数如下：
i2c_1_dsp_master_read卡片（卡片slavechip，uint16 regaddress，uint8 CNT）{
UIT1616MSB =（ReaveAdt & Gt；Gt；8）；
UIT1616LSB＝RealAdvices；
UIT8I；
挥发性U
tiT8状态；
UITN8 RDATA〔4〕；
状态= dsp_i2cmastersendstart（slavechip，dsp_i2c_write_xfer_mode）；
如果（状态= = dsp_i2c_mstr_no_error）/ *检查是否转移无误*结束
{
发送寄存器地址
状态＝DSPIII2CMASTEMWRITE字节（MSB）；
（状态）= DSPII2CYMSTRYNNORY错误）；/ /中断；
Stase= DSP.I2CMistWrrestEnter字节（LSB）；
（状态）= DSPIII2CYMSTRYNONOX错误；
}
状态= dsp_i2cmastersendrestart（slavechip，dsp_i2c_read_xfer_mode）；
If（Stase= DSPGI2CYMSTRIGNONEAR错误）{
/*读取的CNT字节数组*/
对于（i＝0；i＆lt；CNT；i++）
{
如果（我& lt；（CNT））rddata [我] = dsp_i2cmasterreadbyte（dsp_i2c_ack_data）；
否则RDATABAS[I]＝DSPTI2CMASTATEDRADIONTELL（DSPIII2CY-NAKYDATA）；
}
}
DSPGI2cMistSeNestStor（；）/*发送停止*/
DSP2I2CMASTReleRead BuffFor（）；
返回rdDATA〔3〕；
}
每次我看回我得到预期的4字节的登记，使用逻辑分析仪验证。然而，有两件奇怪的事情发生了。
1）即使数组的第四个字节是一样的，因此返回rddata [ 3 ]应始终返回相同的值，这是没有的情况下。第一次i2c_1_dsp_master_read()称为正确的返回值，每次经过它返回0
2）第一次i2c_1_dsp_master_read叫逻辑分析仪显示四字节返回应答，另外一个5字节0x00和NACK看到。每一次，只有4个字节返回，但4字节是现在伴随着一个NACK。请参阅附件。（请注意，即使我提高CNT 5，4字节总是承认，返回值是错误的第一次阅读后。
任何帮助都将非常感谢！
最好的，
卡特琳
屏幕截图2014-01-13在110.7.40.PNG
106.6 K
以上来自于百度翻译
以下为原文
Hi guys,
I have a peculiar problem, which is driving me insane!
I have created a function that is able to read back I2C which includes a 16 bit subaddress.
In my case I need to read back 4 bytes of the subaddress where the value of the 4th byte will be a value of 0, 1 or 2.
if(sleep_counter > 50){
sleep_counter = 0;
readData = I2C_1_DSP_MASTER_READ(DEVICE_ADDR_IC_1, MOD_AUDIO_DETECT_DETECT_REG_READBACKALGSIGMA2001_ADDR, 4);
if(readData == 2 ){
//Do something }
else if(readData == 1 ){
//Do something }
else if(readData == 0){
//Do something
}
}
Where the read function is as follows:
uint8 I2C_1_DSP_MASTER_READ(uint8 slavechip, uint16 regAddress, uint8 cnt ){
uint16 m*** = (regAddress >> 8);
uint16 l*** = regAddress;
uint8 i;
volatile uint8 status;
uint8 rdData[4];
status = DSP_I2CMasterSendStart(slavechip, DSP_I2C_WRITE_XFER_MODE);
if(status == DSP_I2C_MSTR_NO_ERROR) /* Check if transfer completed without errors */
{
// Send register address
status = DSP_I2CMasterWriteByte(m***);
while(status != DSP_I2C_MSTR_NO_ERROR);// break;
status = DSP_I2CMasterWriteByte(l***);
while(status != DSP_I2C_MSTR_NO_ERROR);
}
status = DSP_I2CMasterSendRestart(slavechip, DSP_I2C_READ_XFER_MODE);
if(status == DSP_I2C_MSTR_NO_ERROR) {
/* Read array of cnt bytes */
for(i=0; i
{
if(i < (cnt))rdData=DSP_I2CMasterReadByte(DSP_I2C_ACK_DATA);
else rdData = DSP_I2CMasterReadByte(DSP_I2C_NAK_DATA);
}
}
DSP_I2CMasterSendStop(); /* Send Stop */
DSP_I2CMasterClearReadBuf();
return rdData[3];
}
Every time I read back from the register I get the expected four bytes, verified by using a logic analyzer. However, there are two strange things that happen.
1) Even when the 4th byte of the array stays the same, hence return rdData[3] should always return the same value, this is not the case. First time I2C_1_DSP_MASTER_READ()is called the correct value is returned, every time after that it returns 0
2) The first time I2C_1_DSP_MASTER_READ is called the logic analyzer shows the four bytes returned with ACK, in addition a 5 byte of 0x00 and NACK is seen. Everytime after that 4 bytes only are returned, but the 4 byte is now accompanied by a NACK. Please see attachment. (please note that even if I increase cnt to 5 so that the four bytes are always acknowledged, the return value is still wrong after the first read.
Any help would be very much appreciated!
All the Best,
Katrine
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