PIC18F6520

jamesjl · Joined: 22 Sep 2003 Posts: 52 Location: UK

Hi all,

I am having trouble using a PIC16F877A as it only has one hardware UART. The 18F6520 has two hardware UARTs. Does the PCWH V3.190 complier support both hardware UARTs? Do they have interupts controlling incoming and outgoing data? Do they support an ENABLE pin? What about stream names? Will the complier use the second hardware UART if I specify the correct I/O pins?

My application is communication critical and I think that the timing issues will go away if I use hardware UARTs with interupts for both ports.

Is there anything else that I should consider in moving from the 16F to the 18F uP?

Does anyone have a good source of information, code and schematics for using hardware handshaking with RS232 ports? At the moment my comms is asynchronous and if I could synchronise the Tx and Rx things should go smoother.

Thanks for any help you can give,

Jason.

SteveS · Joined: 27 Oct 2003 Posts: 126

Search the archives - there is a lot of info on this.

In short CCS does support the two ports - I think the readme file has info you should read. Yes, you can use separate interrupts - it is not built in, but you build them like in the serial interrupt examples in the CCS examples or examples in this forum.

Caveat! Some forum membesr have noted problems with the two port parts - so read thru past posts. I've had good luck, so far, but it may be something subtle.

About the biggest problem in moving to the 18F part is figuring out what to do with the extra code space! You do need the PCH compiler and port addresses change. It's pretty painless.

- SteveS

Haplo · Joined: 06 Sep 2003 Posts: 659 Location: Sydney, Australia

In addition to Steve's comments, you might want to look at this post in regards to upwards migration:

http://www.ccsinfo.com/forum/viewtopic.php?t=19167&

Kasper · Posted: Tue May 11, 2004 7:59 am

I had trouble earlier, due to own stupidity, check my post

http://www.ccsinfo.com/forum/viewtopic.php?t=18613&highlight=rs232