Serial Ports for RCM3200


I’m expecting to receive signals from PC3 on the RCM3200. However, to discriminate against noise, I need to take sampled readings of the port for a period of not less than 3 milliseconds.

Does anyone know if it’s possible to sample at, say, 100samples/millisecond?


Are you receiving a serial signal on port PC3, or just a digital signal? If it is serial, you do not need to filter for noise, the UART will handle this. If it is a digital signal then you can sample the port very quickly, especially if you are willing to write some assembly language. In assembly you could be in the 100 samples/millisecond range. Are you trying to qualify that a signal stays high or low for some minimum amount of time before considering it a valid pulse?

I have an 8-bit signal meant to be received serially. So I suppose this quantifies, generally, as a digital signal?

The signal will be of this form:
(1) guard bit, a high for 5ms (required to be high for 95% of any 1ms duration in the 5ms)
(2) low bit (start)
(3) 8 bits of info
(4) high bit (end)

Yes, I’m also looking into the possibility of writing asm code. However, I couldn’t find information regarding the clock cycles and number of instruction cycles per line of code. Hence, I wasn’t sure of how to go about structuring the assembly language code.

Please provide guidance on this. Thank you.


Another question about PC3 on the RCM3200 prototyping board:

I’ve used an oscilloscope to probe the pin PC3 and it registers about 3.2Volts, while there’s no transfer of data to it. I was wondering since it’s an input port (RxC), shouldn’t it register 0 Volts until something is sent to it?

Is there something I should do to initialize it and force it to be an input port? Or can I leave it as its current state and start using it for serial data transfer, which is fed in from a radio receiver?