CCS Bootloader using Software Uart

ntgcp_08 · Joined: 21 Feb 2008 Posts: 24

I've searched for hours trying to find the answer... is it possible to use CCS's loader.c with a software UART?

I've used ex_bootloader.c, bootloader.h, and loader.c with a hardware uart and it works great. If I add FORCE_SW to the #use RS232 statement it doesn't work. Why?

I found the following topic but I have not been able to try it. Why would taking out the XON and XOFF make it work?
http://www.ccsinfo.com/forum/viewtopic.php?t=27980&highlight=software+uart+bootloader

I'm using 18F6722 but I've already used the two hardware Uarts, so I have to run my bootloader with a software Uart. I'm running the PIC at 4Mhz. I've tried setting up the software Uart at 19200, 9600, 4800, and 2400 and none of the baud rates work.

Is there a way to modify loader.c to work with a software Uart?

Guest · Posted: Wed Sep 24, 2008 1:40 pm

Are you sure that the software UART and variables are in 'protected code'? Or are they perhaps being overwritten when you try to overwrite program memory?

Also perhaps you are sending the characters too fast with no inter-character delay time. The software UART is slow as code has to be executed and you are only running at 4 MHz clock...

My thoughts, HTH - Steve H.