HardFaults from a CS4270 I2C driver
Hi All,
So I have an STM32F469 on a PCB I’ve designed with a CS4270 audio codec. I am currently working on an I2C driver to initialize the codec (I am using code from Phil’s lab’s video on writing an I2C driver for the CS4270 - video here), however I seem to be running into a “Bus, memory management or usage fault (FORCED)” and an “Instruction access violation (IACCVIOL)” during an I2C register read function.
Here is the codec init file. The faults happen in this function call:
i2cStatus = CS4270_RegRead(CS4270_REG_DEVICEID, &deviceID);
During one of the debug sessions I decided to “step into” every single instruction from the CS4270_RegWrite function (also going through all the HAL functions underneath) and surprisingly the function returned a HAL_OK, which puzzled me and lead me to believe there maybe some kinda timing issue somewhere, which doesn’t manifest itself when breaking down the instructions one by one. Something worth noting is that initially I had initialized the I2C1 module by mistake (forgetting that my codec was connected on I2C2). Rather than fixing that in CubeMX (the graphical pin assignment) I replaced all the references to I2C1 in the code.
#include "CS4270-Codec.h"
uint8_t CS4270_REG_CONFIG_SETTINGS[8] = {CS4270_DEVICEID, // Device ID
0x00, // Power up
0x31, // Mode (Slave, normal speed, pop guard enable)
0x09, // ADC/DAC (disable HPF, I2S format)
0x00, // Transition (Independent volume controls)
0x12, // Mute right channel
0x00, // DAC A Vol (0dB)
0xFF}; // DAC B Vol (Mute (-127.5dB))
uint8_t CS4270_Init() {
HAL_StatusTypeDef i2cStatus;
// Hard reset of codec
CS4270_Reset();
// Put CODEC in power down mode before adjusting configuration (set freeze bit, power down ADC, DAC, enter low power mode)
i2cStatus = CS4270_RegWrite(CS4270_REG_POWERCONTROL, 0xA3);
if (i2cStatus != HAL_OK) {
return 1;
}
HAL_Delay(500);
// Check device ID
uint8_t deviceID = 0x00;
i2cStatus = CS4270_RegRead(CS4270_REG_DEVICEID, &deviceID);
if ( (i2cStatus != HAL_OK) || ((deviceID & 0xF0) != CS4270_DEVICEID)) { // Upper 4 bits = device ID
return 2;
}
// Set configuration registers
uint8_t regIndex;
uint8_t regData;
for (regIndex = CS4270_REG_DACBVOLCONTROL; regIndex >= CS4270_REG_POWERCONTROL; regIndex--) {
// Write 'default' value to register (Note: not checking reserved bits - default values are 0 in datasheet p.31!)
i2cStatus = CS4270_RegWrite(regIndex, CS4270_REG_CONFIG_SETTINGS[regIndex - 1]);
if (i2cStatus != HAL_OK) {
return regIndex;
}
// Read back register value
i2cStatus = CS4270_RegRead(regIndex, ®Data);
if ((i2cStatus != HAL_OK) || (regData != CS4270_REG_CONFIG_SETTINGS[regIndex - 1])) {
return regIndex;
}
}
return 0;
}
void CS4270_Reset() {
HAL_GPIO_WritePin(CS4270_NRST_GPIO_PORT, CS4270_NRST_GPIO_PIN, GPIO_PIN_SET);
HAL_Delay(75);
HAL_GPIO_WritePin(CS4270_NRST_GPIO_PORT, CS4270_NRST_GPIO_PIN, GPIO_PIN_RESET);
HAL_Delay(75);
HAL_GPIO_WritePin(CS4270_NRST_GPIO_PORT, CS4270_NRST_GPIO_PIN, GPIO_PIN_SET);
HAL_Delay(75);
}
HAL_StatusTypeDef CS4270_RegWrite(uint8_t regAddr, uint8_t regData) {
//return HAL_I2C_Mem_Write(&CS4270_I2C_HANDLE, CS4270_I2C_ADDRESS, regAddr, I2C_MEMADD_SIZE_8BIT, (uint8_t[]){regData}, 1, HAL_MAX_DELAY);
return HAL_I2C_Mem_Write(&CS4270_I2C_HANDLE, CS4270_I2C_ADDRESS, regAddr, I2C_MEMADD_SIZE_8BIT, ®Data, 1, HAL_MAX_DELAY);
}
HAL_StatusTypeDef CS4270_RegRead(uint8_t regAddr, uint8_t *regData) {
return HAL_I2C_Mem_Read(&CS4270_I2C_HANDLE, CS4270_I2C_ADDRESS, regAddr, I2C_MEMADD_SIZE_8BIT, regData, 1, HAL_MAX_DELAY);
}
For context, here’s how the registers look at the fault
What am I missing
Thanks!
