uart_usb_lib.h File Reference

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Functions
void	uart_usb_init (void)
bit	uart_usb_test_hit (void)
char	uart_usb_getchar (void)
bit	uart_usb_tx_ready (void)
int	uart_usb_putchar (int)
void	uart_usb_flush (void)
void	uart_usb_send_buffer (U8 *buffer, U8 nb_data)

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Detailed Description

This file controls the UART USB functions.

• Compiler: IAR EWAVR and GNU GCC for AVR
• Supported devices: AT90USB1287, AT90USB1286, AT90USB647, AT90USB646

Author:

Atmel Corporation: http://www.atmel.com
Support and FAQ: http://support.atmel.no/

Definition in file uart_usb_lib.h.

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Function Documentation

void uart_usb_init

(

void

)

Initializes the uart_usb library

Definition at line 61 of file uart_usb_lib.c.

References rx_counter.

{
  rx_counter = 0;
}

bit uart_usb_test_hit

(

void

)

This function checks if a character has been received on the USB bus.

Returns:

bit (true if a byte is ready to be read)

Definition at line 71 of file uart_usb_lib.c.

References FALSE, Is_device_enumerated, Is_usb_receive_out, rx_counter, RX_EP, Usb_ack_receive_out, Usb_byte_counter, and Usb_select_endpoint.

{
  if(!Is_device_enumerated())
     return FALSE;

  if (!rx_counter)
  {
    Usb_select_endpoint(RX_EP);
    if (Is_usb_receive_out())
    {
      rx_counter = Usb_byte_counter();
      if (!rx_counter)
      {
        Usb_ack_receive_out();
      }
    }
  }
  return (rx_counter!=0);
}

char uart_usb_getchar

(

void

)

This function reads one byte from the USB bus If one byte is present in the USB fifo, this byte is returned. If no data is present in the USB fifo, this function waits for USB data.

Returns:

U8 byte received

Definition at line 99 of file uart_usb_lib.c.

References rx_counter, RX_EP, uart_usb_test_hit(), Usb_ack_receive_out, Usb_read_byte, and Usb_select_endpoint.

{
  register Uchar data_rx;

  Usb_select_endpoint(RX_EP);
  if (!rx_counter) while (!uart_usb_test_hit());
  data_rx=Usb_read_byte();
  rx_counter--;
  if (!rx_counter) Usb_ack_receive_out();
  return data_rx;
}

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bit uart_usb_tx_ready

(

void

)

This function checks if the USB emission buffer is ready to accept at at least 1 byte

Returns:

Boolean. TRUE if the firmware can write a new byte to transmit.

Definition at line 118 of file uart_usb_lib.c.

References FALSE, Is_device_enumerated, Is_usb_write_enabled, and TRUE.

{
  if(!Is_device_enumerated())
     return FALSE;

  if (!Is_usb_write_enabled())
  {
    return FALSE;
  }
  return TRUE;
}

int uart_usb_putchar

(

int

data_to_send

)

This function fills the USB transmit buffer with the new data. This buffer is sent if complete. To flush this buffer before waiting full, launch the uart_usb_flush() function.

Parameters:

data_to_send

Returns:

Definition at line 139 of file uart_usb_lib.c.

References uart_usb_send_buffer().

{
   uart_usb_send_buffer((U8*)&data_to_send, 1);
   return data_to_send;
}

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void uart_usb_flush

(

void

)

void uart_usb_send_buffer	(	U8 *	buffer,
		U8	nb_data
	)

This function transmits a ram buffer content to the USB. This function is mode efficient in term of USB bandwith transfer.

Parameters:

	U8	*buffer : the pointer to the RAM buffer to be sent
	data_to_send	: the number of data to be sent

Definition at line 154 of file uart_usb_lib.c.

References FALSE, Is_device_enumerated, Is_usb_write_enabled, TRUE, TX_EP, TX_EP_SIZE, Usb_ack_in_ready, Usb_select_endpoint, and Usb_write_byte.

{
   U8 zlp;

  if(!Is_device_enumerated())
     return;
   
   // Compute if zlp required
   if(nb_data%TX_EP_SIZE) 
   { zlp=FALSE;} 
   else { zlp=TRUE; }
   
   Usb_select_endpoint(TX_EP);
   while (nb_data)
   {
      while(Is_usb_write_enabled()==FALSE); // Wait Endpoint ready
      while(Is_usb_write_enabled() && nb_data)
      {
         Usb_write_byte(*buffer);
         buffer++;
         nb_data--;
      }
      Usb_ack_in_ready();
   }
   if(zlp)
   {
      while(Is_usb_write_enabled()==FALSE); // Wait Endpoint ready
      Usb_ack_in_ready();
   }
}

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