static void TXInterrupt(int uart_num) {
volatile UART* reg = uart_reg[uart_num];
UART_STATE* uart = &uarts[uart_num];
BYTE_QUEUE* q = &uart->tx_queue;
while (ByteQueueSize(q) && !(reg->uxsta & 0x0200)) {
// TXIF == 1 iff the hardware FIFO is empty. We're just about to make it
// non-empty, so we are safe to clear.
AssignUxTXIF(uart_num, 0);
reg->uxtxreg = ByteQueuePullByte(q);
++uart->num_tx_since_last_report;
}
// IE == 1 iff there is data in the software queue pending to be sent.
AssignUxTXIE(uart_num, ByteQueueSize(q) != 0);
}
void AppProtocolTasks(CHANNEL_HANDLE h) {
if (state == STATE_CLOSED) return;
if (state == STATE_CLOSING && ByteQueueSize(&tx_queue) == 0) {
log_printf("Finished flushing, closing the channel.");
ConnectionCloseChannel(h);
state = STATE_CLOSED;
return;
}
UARTTasks();
SPITasks();
I2CTasks();
ICSPTasks();
if (ConnectionCanSend(h)) {
BYTE prev = SyncInterruptLevel(1);
const BYTE* data;
if (bytes_out) {
ByteQueuePull(&tx_queue, bytes_out);
bytes_out = 0;
}
ByteQueuePeek(&tx_queue, &data, &bytes_out);
if (bytes_out > 0) {
if (bytes_out > max_packet) bytes_out = max_packet;
ConnectionSend(h, data, bytes_out);
}
SyncInterruptLevel(prev);
}
}
