diff options
Diffstat (limited to 'Demos/Device/USBtoSerial/USBtoSerial.c')
| -rw-r--r-- | Demos/Device/USBtoSerial/USBtoSerial.c | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/Demos/Device/USBtoSerial/USBtoSerial.c b/Demos/Device/USBtoSerial/USBtoSerial.c index 87d531c4d..1d238aa11 100644 --- a/Demos/Device/USBtoSerial/USBtoSerial.c +++ b/Demos/Device/USBtoSerial/USBtoSerial.c @@ -246,18 +246,19 @@ TASK(CDC_Task) if (Endpoint_IsOUTReceived())
{
- /* Read the received data endpoint into the transmission buffer */
- while (Endpoint_BytesInEndpoint())
+ /* Read the bytes in from the endpoint into the buffer while space is available */
+ while (Endpoint_BytesInEndpoint() && (BUFF_STATICSIZE - Rx_Buffer.Elements))
{
- /* Wait until the buffer has space for a new character */
- while (!((BUFF_STATICSIZE - Rx_Buffer.Elements)));
-
/* Store each character from the endpoint */
Buffer_StoreElement(&Rx_Buffer, Endpoint_Read_Byte());
}
- /* Clear the endpoint buffer */
- Endpoint_ClearOUT();
+ /* Check to see if all bytes in the current packet have been read */
+ if (!(Endpoint_BytesInEndpoint()))
+ {
+ /* Clear the endpoint buffer */
+ Endpoint_ClearOUT();
+ }
}
/* Check if Rx buffer contains data */
@@ -280,18 +281,29 @@ TASK(CDC_Task) /* Wait until Serial Tx Endpoint Ready for Read/Write */
while (!(Endpoint_IsReadWriteAllowed()));
- /* Write the transmission buffer contents to the received data endpoint */
+ /* Write the bytes from the buffer to the endpoint while space is available */
while (Tx_Buffer.Elements && (Endpoint_BytesInEndpoint() < CDC_TXRX_EPSIZE))
- Endpoint_Write_Byte(Buffer_GetElement(&Tx_Buffer));
+ {
+ /* Write each byte retreived from the buffer to the endpoint */
+ Endpoint_Write_Byte(Buffer_GetElement(&Tx_Buffer));
+ }
+
+ /* Remember if the packet to send completely fills the endpoint */
+ bool IsFull = (Endpoint_BytesInEndpoint() == CDC_TXRX_EPSIZE);
/* Send the data */
Endpoint_ClearIN();
- /* Wait until Serial Tx Endpoint Ready for Read/Write */
- while (!(Endpoint_IsReadWriteAllowed()));
+ /* If no more data to send and the last packet filled the endpoint, send an empty packet to release
+ * the buffer on the receiver (otherwise all data will be cached until a non-full packet is received) */
+ if (IsFull && !(Tx_Buffer.Elements))
+ {
+ /* Wait until Serial Tx Endpoint Ready for Read/Write */
+ while (!(Endpoint_IsReadWriteAllowed()));
- /* Send an empty packet to terminate the transfer */
- Endpoint_ClearIN();
+ /* Send an empty packet to terminate the transfer */
+ Endpoint_ClearIN();
+ }
}
}
}
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