Post by thread:16C84 program memory above 100h

This is probably a FAQ but . . . What happens to code put above 100h in the 16C84? Do I have to use long calls or is my PIC substandard? Anything put above there refuses to run! /\/\att.

Matthew Rowe <matt%spam_OUTatlas.king.ac.ukTakeThisOuTUKACRL.BITNET> wrote: >What happens to code put above 100h in the 16C84? >Do I have to use long calls or is my PIC substandard? >Anything put above there refuses to run! Matt: It's not "anything" that refuses to run, it's just computed GOTOs (ADDWF PCL, MOVWF PCL, etc.)... Right? If so, the problem is that you're not properly setting/restoring PCLATH. See Section 4.3 in the 16C84 Data Sheet, and Appnote AN556 in the Embedded Control Handbook. By the way, you can ignore the appnote section which says that you must disable interrupts around computed GOTOs; it's wrong. -Andy -- Andrew Warren - .....fastfwdKILLspam@spam@ix.netcom.com Fast Forward Engineering, Vista, California

>This is probably a FAQ but . . . > >What happens to code put above 100h in the 16C84? >Do I have to use long calls or is my PIC substandard? >Anything put above there refuses to run! > >/\/\att. I never had any problems, like those with the 16C5x's. I don't think the 16C84 has long calls or program memory page switching. Once I left the END directive before code I pasted into my program. Of course the pasted code neither assembled or ran. Check your code again.

> >What happens to code put above 100h in the 16C84? > >Do I have to use long calls or is my PIC substandard? > >Anything put above there refuses to run! > It's not "anything" that refuses to run, it's just computed GOTOs > (ADDWF PCL, MOVWF PCL, etc.)... Right? yes, you're right. I've since got round it by putting the lookup table at the start of my code. > If so, the problem is that you're not properly setting/restoring > PCLATH. See Section 4.3 in the 16C84 Data Sheet, and Appnote AN556 in > the Embedded Control Handbook. Will do for future reference. Thanks.