// output ASCII character to UART
// block if TxFifo is full
void UART_OutChar(char data){
while(TxFifo_Put(data) == FIFOFAIL){
OS_Wait(&TxRoomLeft);
}
UART0_IM_R &= ~UART_IM_TXIM; // disable TX FIFO interrupt
copySoftwareToHardware();
UART0_IM_R |= UART_IM_TXIM; // enable TX FIFO interrupt
}
// at least one of three things has happened:
// hardware TX FIFO goes from 3 to 2 or less items
// hardware RX FIFO goes from 1 to 2 or more items
// UART receiver has timed out
void UART0_Handler(void){
if(UART0_RIS_R&UART_RIS_TXRIS){ // hardware TX FIFO <= 2 items
UART0_ICR_R = UART_ICR_TXIC; // acknowledge TX FIFO
// copy from software TX FIFO to hardware TX FIFO
copySoftwareToHardware();
if(TxFifo_Size() == 0){ // software TX FIFO is empty
UART0_IM_R &= ~UART_IM_TXIM; // disable TX FIFO interrupt
}
}
if(UART0_RIS_R&UART_RIS_RXRIS){ // hardware RX FIFO >= 2 items
UART0_ICR_R = UART_ICR_RXIC; // acknowledge RX FIFO
// copy from hardware RX FIFO to software RX FIFO
copyHardwareToSoftware();
}
if(UART0_RIS_R&UART_RIS_RTRIS){ // receiver timed out
UART0_ICR_R = UART_ICR_RTIC; // acknowledge receiver time out
// copy from hardware RX FIFO to software RX FIFO
copyHardwareToSoftware();
}
}
//------------UART_OutCharNonBlock------------
// non blocking output ASCII character to UART
// Input: letter is an 8-bit ASCII character to be transferred
// Output: none
// Error: return with lost data if TxFifo is full
void UART_OutCharNonBlock(char data){
if(TxFifo_Put(data) == FIFOFAIL) return; // lost data
UART0_IM_R &= ~UART_IM_TXIM; // disable TX FIFO interrupt
copySoftwareToHardware();
UART0_IM_R |= UART_IM_TXIM; // enable TX FIFO interrupt
}
// output ASCII character to UART
// spin if TxFifo is full
void UART_OutChar(unsigned char data){
while(TxFifo_Put(data) == FIFOFAIL){};
UART0_IM_R &= ~UART_IM_TXIM; // disable TX FIFO interrupt
copySoftwareToHardware();
UART0_IM_R |= UART_IM_TXIM; // enable TX FIFO interrupt
}
