void ring_buffer_read(ring_buffer* ring, uint8_t* buffer, uint16_t size) {
uint16_t i;
// TODO can be optimized
for(i = 0; i < size; i++) {
buffer[i] = ring_buffer_read_byte(ring);
}
}
/* _____LOCAL FUNCTIONS______________________________________________________ */
static void usart0_interrupt(void)
{
u8_t data;
// Read status register
u32_t csr = AT91C_BASE_US0->US_CSR;
// See if a receive error was detected
if(csr & (AT91C_US_RXBRK | AT91C_US_OVRE | AT91C_US_FRAME | AT91C_US_PARE))
{
// Reset status bits
AT91C_BASE_US0->US_CR = AT91C_US_RSTSTA;
return;
}
// See if a character has been received
if(csr & AT91C_US_RXRDY)
{
// Read character and buffer it
data = (char)(AT91C_BASE_US0->US_RHR);
ring_buffer_write_byte(&usart0_rx_ring_buffer, data);
}
// See if the transmitter is ready
if(csr & AT91C_US_TXRDY)
{
// See if there is more data to be sent
if(ring_buffer_read_byte(&usart0_tx_ring_buffer,&data))
{
// Clear flag to indicate that transmission is busy
usart0_tx_finished_flag = FALSE;
// Buffer data to be transmitted
AT91C_BASE_US0->US_THR = data;
}
else
{
// Disable transmit ready interrupt
AT91C_BASE_US0->US_IDR = AT91C_US_TXRDY;
// Enable transmit empty interrupt
AT91C_BASE_US0->US_IER = AT91C_US_TXEMPTY;
}
}
// See if the transmitter is finished
if(csr & AT91C_US_TXEMPTY)
{
// Set flag to indicate that transmission is finished
usart0_tx_finished_flag = TRUE;
// Disable transmit empty interrupt
AT91C_BASE_US0->US_IDR = AT91C_US_TXEMPTY;
}
}
bool_t usart0_get_rx_byte(u8_t* data)
{
return ring_buffer_read_byte(&usart0_rx_ring_buffer,data);
}
