STM32F207ZE I2C fails during Master read

[redfieldm]

Posted on May 30, 2015 at 00:11

Hi,

I'm using I2CSTM32F207ZET6. It usually works well, and we can usually read and write with no problems. However, there is a consistent error that pops up where, if we are reading a number of bytes sequentially, the reads will fail. After that, it looks like the STM32 goes through several I2C addresses polling for an available slave (I'm not sure why this is happening now). We've captured this on a logic analyzer. This behavior happens every time the error occurs. This picture shows the I2C bus correctly reading sequential data from an EEPROM. At some point, the STM32 acks a received byte and then the clock duty cycle changes for a bit. After that, it looks like the STM32 tries to cycle through various slave addresses (starting from the address of my EEPROM+2). Here's how I'm setting up the I2C bus:

//Setup the i2c bus
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStruct;
// I2C2 clock enable 
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
// GPIOF clock enable 
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);
// Connect I2C2 pins to AF4 ***********************************************
GPIO_PinAFConfig(GPIOF, GPIO_PinSource0, GPIO_AF_I2C2);
GPIO_PinAFConfig(GPIOF, GPIO_PinSource1, GPIO_AF_I2C2);
// Configure I2C2 GPIOs ***************************************************
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOF, &GPIO_InitStructure);
// Configure I2C2 *********************************************************
// I2C DeInit 
I2C_DeInit(I2C2);
// Enable the I2C peripheral 
I2C_Cmd(I2C2, ENABLE);
// Set the I2C structure parameters 
I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStruct.I2C_OwnAddress1 = 0xFE;
I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStruct.I2C_ClockSpeed = 200000; // full speed clock rate causes I2C bus to periodically fail, so using 200k instead
// Initialize the I2C peripheral w/ selected parameters 
I2C_Init(I2C2, &I2C_InitStruct);

Here's the code I'm using to read from the EEPROM.

bool
rx_Eeprom_Data(
int
addr, unsigned 
char
* data, 
int
data_len)
{
uint32_t timeout = TIMEOUT_MAX;
uint8_t tx_data[2];
tx_data[1] = addr & 0xFF;
tx_data[0] = addr >> 8;
// Generate the Start Condition 
I2C_GenerateSTART(I2C2, ENABLE);
// Test on I2C2 EV5 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
// Send DCMI selcted device slave Address for write 
I2C_Send7bitAddress(I2C2, EEPROM_ADDX, I2C_Direction_Transmitter);
// Test on I2C2 EV6 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
for
(
int
j = 0; j < 2; j++)
{
// Send Data 
I2C_SendData(I2C2, tx_data[j]);
// Test on I2C2 EV8 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
}
// Generate the Start Condition 
I2C_GenerateSTART(I2C2, ENABLE);
// Test on I2C2 EV5 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
// Send DCMI selcted device slave Address for read 
I2C_Send7bitAddress(I2C2, EEPROM_ADDX, I2C_Direction_Receiver);
// Test on I2C2 EV6 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
for
(
int
j = 0; j < data_len - 1; j++)
{
// Prepare an ACK for the next data received 
I2C_AcknowledgeConfig(I2C2, ENABLE);
// Test on I2C2 EV8 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
data[j] = I2C_ReceiveData(I2C2);
}
// Prepare an NACK for the next data received 
I2C_AcknowledgeConfig(I2C2, DISABLE);
// Test on I2C2 EV8 and clear it 
timeout = TIMEOUT_MAX; 
// Initialize timeout value 
while
(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
{
// If the timeout delay is exeeded, exit with error code 
if
((timeout--) == 0) 
return
false
;
}
// Send I2C2 STOP Condition 
I2C_GenerateSTOP(I2C2, ENABLE);
data[data_len - 1] = I2C_ReceiveData(I2C2);
return
true
;
}