#8 AT91SAM7 UART h/w flow control or DMA

[Harald Kipp]

Reported in the mailing list:

I'm interfacing the AT91SAM7 port of NutOS with a modem
that requires
RTS/CTS flow control. But as far as I can tell the
USART driver (low level
parts in arch/arm/dev/usartat91.c) doesn't support
this. Well ... there's
support for it, but it looks AVR-only and is
essentially commented out. It
looks like it wouldn't be too much work to port it
over, but there are a few
hardware-dependent bits.

Plus, it's done in software, and the AT91 supports a
nice RTS/CTS hardware
flow control mode ("hardware handshaking"). But it only
works in DMA (PDC)
mode (for reception, at least).

[Harald Kipp]

Logged In: YES
user_id=303906

Added a comment, which states, that this is currently not
available.

Changed bug report to feature request.

[Nobody/Anonymous]

Don't trust the Sam's hw flow control mechanism. It is much safer to implement your own style. You can still use the DMA and RTS/CTS defined pins but let the driver control them