于 2013年07月08日 15:50, Russell King - ARM Linux 写道:
On Sun, Jul 07, 2013 at 01:51:14PM +0200, Lothar Waßmann wrote:
Hi,
Shawn Guo writes:
On Fri, Jul 05, 2013 at 02:12:30PM +0800, Huang Shijie wrote:
There is something wrong with the RTS/CTS pads:
The RTS pad is assigned with the CTS's value;
while the CTS pad is assigned with the RTS's value.
So basically, you are saying that select_input should be set up for CTS
rather than RTS. It seems that the people who generated the macro got
the wrong input from developer.
programming 'select_input' only makes sense for inputs, not outputs.
Since CTS is an output signal, select_input only makes sense for the
RTS function of the pads.
Note: If you are a DTE, then RTS is an output, CTS is an input. If you
are a DCE, then RTS is an input and CTS is an output (normally on a
standard UART, you just swap the wiring for RTS and CTS but really that's
all that is going on.) So swapping them in software should be acceptable
too, provided you're not having to disable any auto flow control facilities.
thanks for explanation.
Huang Shijie
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