void STM32_I2C_EV_Interrupt (void* param) // Event Interrupt Handler
{
INTERRUPT_START
// pre:
// I2C_SR1_SB | I2C_SR1_ADDR | I2C_SR1_BTF | I2C_CR2_ITBUFEN & (I2C_SR1_RXNE | I2C_SR1_TXE)
I2C_HAL_XACTION* xAction = currentI2CXAction;
I2C_HAL_XACTION_UNIT* unit = currentI2CUnit;
int todo = unit->m_bytesToTransfer;
int sr1 = I2Cx->SR1; // read status register
int sr2 = I2Cx->SR2; // clear ADDR bit
int cr1 = I2Cx->CR1; // initial control register
if (unit->IsReadXActionUnit()) { // read transaction
if (sr1 & I2C_SR1_SB) { // start bit
if (todo == 1) {
I2Cx->CR1 = (cr1 &= ~I2C_CR1_ACK); // last byte nack
} else if (todo == 2) {
I2Cx->CR1 = (cr1 |= I2C_CR1_POS); // prepare 2nd byte nack
}
UINT8 addr = xAction->m_address << 1; // address bits
I2Cx->DR = addr + 1; // send header byte with read bit;
} else {
if (sr1 & I2C_SR1_ADDR) { // address sent
if (todo == 1) {
I2Cx->CR1 = (cr1 |= I2C_CR1_STOP); // send stop after single byte
} else if (todo == 2) {
I2Cx->CR1 = (cr1 &= ~I2C_CR1_ACK); // last byte nack
}
} else {
while (sr1 & I2C_SR1_RXNE) { // data available
if (todo == 2) { // 2 bytes remaining
I2Cx->CR1 = (cr1 |= I2C_CR1_STOP); // stop after last byte
} else if (todo == 3) { // 3 bytes remaining
if (!(sr1 & I2C_SR1_BTF)) break; // assure 2 bytes are received
I2Cx->CR1 = (cr1 &= ~I2C_CR1_ACK); // last byte nack
}
UINT8 data = I2Cx->DR; // read data
*(unit->m_dataQueue.Push()) = data; // save data
unit->m_bytesTransferred++;
unit->m_bytesToTransfer = --todo; // update todo
sr1 = I2Cx->SR1; // update status register copy
}
}
if (todo == 1) {
I2Cx->CR2 |= I2C_CR2_ITBUFEN; // enable I2C_SR1_RXNE interrupt
}
}
} else { // write transaction
if (sr1 & I2C_SR1_SB) { // start bit
UINT8 addr = xAction->m_address << 1; // address bits
I2Cx->DR = addr; // send header byte with write bit;
} else {
while (todo && (sr1 & I2C_SR1_TXE)) {
I2Cx->DR = *(unit->m_dataQueue.Pop()); // next data byte;
unit->m_bytesTransferred++;
unit->m_bytesToTransfer = --todo; // update todo
sr1 = I2Cx->SR1; // update status register copy
}
if (!(sr1 & I2C_SR1_BTF)) todo++; // last byte not yet sent
}
}
if (todo == 0) { // all received or all sent
if (!xAction->ProcessingLastUnit()) { // start next unit
I2Cx->CR2 &= ~I2C_CR2_ITBUFEN; // disable I2C_SR1_RXNE interrupt
currentI2CUnit = xAction->m_xActionUnits[ xAction->m_current++ ];
I2Cx->CR1 = I2C_CR1_PE | I2C_CR1_START | I2C_CR1_ACK; // send restart
} else {
xAction->Signal(I2C_HAL_XACTION::c_Status_Completed); // calls XActionStop()
}
}
INTERRUPT_END
}
void STM32_I2C_EV_Interrupt (void* param) // Event Interrupt Handler
{
INTERRUPT_START
I2C_HAL_XACTION* xAction = currentI2CXAction;
I2C_HAL_XACTION_UNIT* unit = currentI2CUnit;
int todo = unit->m_bytesToTransfer;
int sr1 = I2Cx->SR1; // read status register
int sr2 = I2Cx->SR2; // clear ADDR bit
int cr1 = I2Cx->CR1; // initial control register
if (unit->IsReadXActionUnit()) { // read transaction
if (todo > 0) {
if (sr1 & I2C_SR1_SB) { // start bit
if (todo == 2) {
I2Cx->CR1 = (cr1 |= I2C_CR1_POS); // prepare 2nd byte nack
}
UINT8 addr = xAction->m_address << 1; // address bits
I2Cx->DR = addr + 1; // send header byte with read bit;
} else {
if (sr1 & I2C_SR1_ADDR) { // address sent
if (todo <= 2) {
if (todo == 1) cr1 |= I2C_CR1_STOP; // send stop after single byte
I2Cx->CR1 = (cr1 &= ~I2C_CR1_ACK); // last byte nack
}
} else {
int n = 0;
if (sr1 & I2C_SR1_BTF) { // two bytes available
n = (todo & 1) + 1; // todo odd => read two bytes
if (todo == 2) n = 2; // todo = 2 => read all
if (todo == 3) {
I2Cx->CR1 = (cr1 &= ~I2C_CR1_ACK); // last byte nack
}
} else if (todo == 1 && sr1 & I2C_SR1_RXNE) { // last byte
n = 1;
I2Cx->CR2 &= ~I2C_CR2_ITBUFEN; // disable I2C_SR1_RXNE interrupts
}
while (n != 0) {
if (todo == 2) {
I2Cx->CR1 = (cr1 |= I2C_CR1_STOP); // stop after last byte
}
UINT8 data = I2Cx->DR; // read data
*(unit->m_dataQueue.Push()) = data; // save data
unit->m_bytesTransferred++;
unit->m_bytesToTransfer = --todo; // update todo
n--;
}
}
if (todo == 1) {
I2Cx->CR2 |= I2C_CR2_ITBUFEN; // enable I2C_SR1_RXNE interrupt
}
}
}
} else { // write transaction
if (sr1 & I2C_SR1_SB) { // start bit
UINT8 addr = xAction->m_address << 1; // address bits
I2Cx->DR = addr; // send header byte with write bit;
} else if (sr1 & I2C_SR1_ADDR || sr1 & I2C_SR1_BTF) { // tx idle
int n = todo < 2 ? todo : 2; // write at most 2 bytes
while (n != 0) {
I2Cx->DR = *(unit->m_dataQueue.Pop()); // next data byte;
unit->m_bytesTransferred++;
unit->m_bytesToTransfer--; // no todo update!
n--;
}
}
}
if (todo == 0) {
if (!xAction->ProcessingLastUnit()) { // start next unit
currentI2CUnit = xAction->m_xActionUnits[ xAction->m_current++ ];
I2Cx->CR1 = I2C_CR1_PE | I2C_CR1_START | I2C_CR1_ACK; // send restart
} else {
xAction->Signal(I2C_HAL_XACTION::c_Status_Completed); // calls XActionStop()
}
}
INTERRUPT_END
}
void LPC178X_I2C_Driver::ISR( void* arg )
{
UINT8 address;
LPC178X_I2C& I2C = LPC178X::I2C();
// read status
volatile UINT32 status;
I2C_HAL_XACTION* xAction = g_LPC178X_I2C_Driver.m_currentXAction;
I2C_HAL_XACTION_UNIT* unit = g_LPC178X_I2C_Driver.m_currentXActionUnit;
ASSERT(xAction);
ASSERT(unit);
status = I2C.I2STAT & 0xFF;
switch(status)
{
case 0x08: // Start Condition transmitted
case 0x10: // Repeated Start Condition transmitted
// Write Subordinate address and Data direction
address = 0xFE & (xAction->m_address << 1);
address |= unit->IsReadXActionUnit() ? LPC178X_I2C_Driver::c_DirectionRead : LPC178X_I2C_Driver::c_DirectionWrite;
I2C.I2DAT = address;
// Clear STA bit
I2C.I2CONCLR = LPC178X_I2C::STA;
break;
case 0x18: // Subordinate Address + W transmitted, Ack received
case 0x28: // Data transmitted, Ack received
// Write data
// transaction completed
if(unit->m_bytesToTransfer == 0)
{
if(xAction->ProcessingLastUnit())
{
xAction->Signal( I2C_HAL_XACTION::c_Status_Completed );
}
else
{
MasterXAction_Start( xAction, true );
}
}
else
{
WriteToSubordinate( unit );
}
break;
case 0x20: // Write Address not acknowledged by Subordinate
case 0x30: // Data not acknowledged by Subordinate
case 0x48: // Read Address not acknowledged by Subordinate
xAction->Signal( I2C_HAL_XACTION::c_Status_Aborted );
break;
case 0x38: // Arbitration lost
xAction->Signal( I2C_HAL_XACTION::c_Status_Aborted );
break;
case 0x40: // Subordinate Address + R transmitted, Ack received
// if the transaction is one byte only to read, then we must send NAK immediately
if(unit->m_bytesToTransfer == 1)
{
I2C.I2CONCLR = LPC178X_I2C::AA;
}
else
{
I2C.I2CONSET = LPC178X_I2C::AA;
}
break;
case 0x50: // Data received, Ack Sent
case 0x58: // Data received, NO Ack sent
// read next byte
ReadFromSubordinate( unit );
if(unit->m_bytesToTransfer == 1)
{
I2C.I2CONCLR = LPC178X_I2C::AA;
}
if(unit->m_bytesToTransfer == 0)
{
if(xAction->ProcessingLastUnit())
{
// send transaction stop
xAction->Signal( I2C_HAL_XACTION::c_Status_Completed );
}
else
{
// start next
MasterXAction_Start( xAction, true );
}
}
break;
case 0x00: // Bus Error
// Clear Bus error
I2C.I2CONSET = LPC178X_I2C::STO;
xAction->Signal( I2C_HAL_XACTION::c_Status_Aborted );
break;
default:
xAction->Signal( I2C_HAL_XACTION::c_Status_Aborted );
break;
} // switch(status)
// clear the interrupt flag to start the next I2C transfer
I2C.I2CONCLR = LPC178X_I2C::SI;
}