Hello All, I am implementing hardware handshaking with USART on AT91RM9200 board (24.6.3.12 in data sheet). I need to make RTS signal orignating from CP drop to allow the remote device with which the CPU is communicating t transmit information to the CPU. The data sheet states that the USAR needs requires the use of the PDC (peripheral DMA controller) fo reception when using hardware handshaking. I have used the PD successfully before to talk (send/receive) to other peripherals, and ca successfully use it to send out the USART, but even though I believe t have configured the PDC reception correctly, the RTS signal does not dro low. Is there something else that I need to do besides set up PDC an enable receive on USART? Another Question: Does hardware handshaking work for both synchronous and asynchronou transmission? I assume so, as I haven't read otherwise in the dat sheet. Thank you very much for your help. Joshua This message was sent using the comp.arch.embedded web interface o www.EmbeddedRelated.com
PDC w/ USART
Started by ●July 9, 2005
Reply by ●July 13, 20052005-07-13
The problem is that the RTS line for USART 0 isn't brought out to the lin that it is supposed to (RTS0 is PA21 in data sheet). AT91RM9200 Errat sheet states that it is brought out to PD21. When setting up USART 0 t use PD21, the RTS line will assert low as it is supposed to.>Hello All, > >I am implementing hardware handshaking with USART on AT91RM9200 board >(24.6.3.12 in data sheet). I need to make RTS signal orignating from CP >drop to allow the remote device with which the CPU is communicating t >transmit information to the CPU. The data sheet states that the USAR >needs requires the use of the PDC (peripheral DMA controller) fo >reception when using hardware handshaking. I have used the PD >successfully before to talk (send/receive) to other peripherals, and ca >successfully use it to send out the USART, but even though I believe t >have configured the PDC reception correctly, the RTS signal does not dro >low. Is there something else that I need to do besides set up PDC an >enable receive on USART? > >Another Question: > >Does hardware handshaking work for both synchronous and asynchronou >transmission? I assume so, as I haven't read otherwise in the dat >sheet. > >Thank you very much for your help. > >Joshua > > > >This message was sent using the comp.arch.embedded web interface o >www.EmbeddedRelated.com >This message was sent using the comp.arch.embedded web interface o www.EmbeddedRelated.com