implement i2c write
This commit is contained in:
parent
695e5dc9f4
commit
df482ca7c4
32
main.c
32
main.c
|
@ -48,8 +48,14 @@ static bool hpd_fwd = false; // if the I²C source line is connected to sink
|
|||
|
||||
// if an I²C transaction started
|
||||
static volatile bool i2c_transaction_new = false;
|
||||
// if an I²C transaction with new data started
|
||||
// if an I²C transaction with incoming data started
|
||||
static volatile bool i2c_input_new = false;
|
||||
// if the byte should be programmed
|
||||
static volatile bool i2c_prog = false;
|
||||
// the address of the byte to be read or programmed
|
||||
static volatile uint8_t i2c_addr = 0;
|
||||
// the data to be programmed
|
||||
static volatile uint8_t i2c_data = 0;
|
||||
|
||||
// blocking wait (in 10 us steps, up to UINT32_MAX / 10)
|
||||
static void wait_10us(uint32_t us10)
|
||||
|
@ -510,25 +516,21 @@ void awu(void) __interrupt(IRQ_AWU) // auto wakeup
|
|||
|
||||
void i2c(void) __interrupt(IRQ_I2C) // auto wakeup
|
||||
{
|
||||
static uint8_t addr = 0; // EEPROM address to read
|
||||
// make copies of status registers, since some bits might be cleared meanwhile
|
||||
const uint8_t sr1 = I2C_SR1;
|
||||
const uint8_t sr2 = I2C_SR2;
|
||||
const uint8_t sr3 = I2C_SR3; // clears ADDR after reading SR1
|
||||
if (sr1 & I2C_SR1_TXE) { // transmission buffer is empty
|
||||
// transmit next byte
|
||||
if (eeprom_valid) {
|
||||
I2C_DR = *(uint8_t*)(EEPROM_ADDR + addr++);
|
||||
} else {
|
||||
I2C_DR = 0xff;
|
||||
}
|
||||
I2C_DR = *(uint8_t*)(EEPROM_ADDR + i2c_addr++); // transmit next byte (even if invalid)
|
||||
}
|
||||
if (sr1 & I2C_SR1_RXNE) { // receive buffer is full
|
||||
const uint8_t data = I2C_DR; // read data (also clears flag)
|
||||
if (I2C_CR2 & I2C_CR2_ACK) {
|
||||
addr = data; // we only take the first address byte
|
||||
i2c_data = I2C_DR; // read data (also clears flag)
|
||||
if (i2c_input_new) { // we just received the first byte
|
||||
i2c_addr = i2c_data; // we only take the first address byte
|
||||
i2c_input_new = false; // next byte is not the first
|
||||
} else { // received data byte
|
||||
i2c_prog = true; // notify main loop data needs to be programmed
|
||||
}
|
||||
I2C_CR2 &= I2C_CR2_ACK; // NACK next received byte
|
||||
}
|
||||
if (sr1 & I2C_SR1_STOPF) { // stop received
|
||||
I2C_CR2 |= I2C_CR2_ACK; // this is just to clear the flag
|
||||
|
@ -536,11 +538,7 @@ void i2c(void) __interrupt(IRQ_I2C) // auto wakeup
|
|||
if (sr1 & I2C_SR1_ADDR) { // our slave address has been selected
|
||||
i2c_transaction_new = true; // notify main loop transaction started
|
||||
if (sr3 & I2C_SR3_TRA) { // start data transmission
|
||||
if (eeprom_valid) {
|
||||
I2C_DR = *(uint8_t*)(EEPROM_ADDR + addr++); // transmit selected byte
|
||||
} else {
|
||||
I2C_DR = 0xff;
|
||||
}
|
||||
I2C_DR = *(uint8_t*)(EEPROM_ADDR + i2c_addr++); // transmit selected byte
|
||||
i2c_input_new = false; // notify we send data
|
||||
} else { // we will receive data
|
||||
I2C_CR2 |= I2C_CR2_ACK; // ACK next received byte
|
||||
|
|
Loading…
Reference in New Issue