Serials in RCM3700
Started by ●January 12, 2005
I am using the RCM3700 module and I need to know if it is possible
have 4 serials RS232. I have this doubt because in the connector there
are 2 serials with the same pins. How can I do it?
Thanks
Albert
Reply by ●January 12, 20052005-01-12
Albert,
It is possible to use up to 5 serial ports on the RCM3700, but going
beyond 3 ports requires possibly losing some other options. Serial
port F shares pins with the receive lines for serial ports C & D.
This means if you are trying to maximize serial ports, port F should
probably not be used. You always have the option of using serial
port A which is available on the programming connector, with the
downside of not being able to run a debugging session.
You can also access serial port B on its alternate pins (port D, pins
4 & 5). Serial port B is used to interface to the onboard serial
flash. If you don't need the onboard serial flash, then you can
simply change port C pins 4 & 5 to normal input/output and enable the
alternate functions of port D pins 4 & 5 to have full access to
serial port B.
If you need the serial flash, you can do this same switch-over of pin
functions on the fly and "share" port B with the serial flash. This
would mean that when using the serial flash, you would lose access to
the device you have connected to PD4 & PD5, and vice versa. If you
can live with communicating to a device on a part time basis,
this "switching back and forth method" is not that difficult to
accomplish.
The only other option to increase serial ports is if you have a
couple of devices that you only need to send data to, and never
receive data from. If this is the case you can set the receive pin
of serial port D (PC1) to a normal input, then set PG2 to its
alternate function which is the transmit line for serial port F. In
this configuration, you could transmit only on serial ports D & F,
and would have two way communications available on serial ports C & E.
I hope one of these configurations will work for you. If not, you
might want to move to an RCM3000 or RCM3300 board which has more pins
available to the outside world.
Bill Sprouse
Z-World, Inc.
--- In rabbit-semi@rabb..., "cargemalb" <aorta@s...> wrote:
>
> I am using the RCM3700 module and I need to know if it is possible
> have 4 serials RS232. I have this doubt because in the connector
there
> are 2 serials with the same pins. How can I do it?
>
> Thanks
>
> Albert
Reply by ●February 4, 20052005-02-04
Do you have an example of how to implement this. I think I am
missing something since nothing seems to work.
David Troike --- In rabbit-semi@rabb..., "billsprouse" <wsprouse@z...>
wrote:
>
> Albert,
>
> It is possible to use up to 5 serial ports on the RCM3700, but
going
> beyond 3 ports requires possibly losing some other options. Serial
> port F shares pins with the receive lines for serial ports C & D.
> This means if you are trying to maximize serial ports, port F
should
> probably not be used. You always have the option of using serial
> port A which is available on the programming connector, with the
> downside of not being able to run a debugging session.
>
> You can also access serial port B on its alternate pins (port D,
pins
> 4 & 5). Serial port B is used to interface to the onboard serial
> flash. If you don't need the onboard serial flash, then you can
> simply change port C pins 4 & 5 to normal input/output and enable
the
> alternate functions of port D pins 4 & 5 to have full access to
> serial port B.
>
> If you need the serial flash, you can do this same switch-over of
pin
> functions on the fly and "share" port B with the serial flash.
This
> would mean that when using the serial flash, you would lose access
to
> the device you have connected to PD4 & PD5, and vice versa. If you
> can live with communicating to a device on a part time basis,
> this "switching back and forth method" is not that difficult to
> accomplish.
>
> The only other option to increase serial ports is if you have a
> couple of devices that you only need to send data to, and never
> receive data from. If this is the case you can set the receive pin
> of serial port D (PC1) to a normal input, then set PG2 to its
> alternate function which is the transmit line for serial port F.
In
> this configuration, you could transmit only on serial ports D & F,
> and would have two way communications available on serial ports C &
E.
>
> I hope one of these configurations will work for you. If not, you
> might want to move to an RCM3000 or RCM3300 board which has more
pins
> available to the outside world.
>
> Bill Sprouse
> Z-World, Inc.
>
> --- In rabbit-semi@rabb..., "cargemalb" <aorta@s...> wrote:
> >
> > I am using the RCM3700 module and I need to know if it is possible
> > have 4 serials RS232. I have this doubt because in the connector
> there
> > are 2 serials with the same pins. How can I do it?
> >
> > Thanks
> >
> > Albert
