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jsr changing registers in 68hc11?

Started by Mr Dump April 4, 2007
Hi All, I hope this is the right forum, I have a 68hc11
microcontroller, and im using BR to debug my buggy code (it has the
Buffalo monitor)
The gist of it is: I load numbers into registers and then jump to a
subroutine, i check the numbers before and after the jump, but they
have changed- any clues to what is happening?
cheers,
dt

On Apr 4, 9:56 am, "Mr Dump" <dth42...@bigpond.net.au> wrote:

> The gist of it is: I load numbers into registers and then jump to a > subroutine, i check the numbers before and after the jump, but they > have changed- any clues to what is happening?
Is an interrupt occuring? When you say "registers", do you mean MCU registers or I/O control registers? Buffalo is not a very good way to debug since it is invasive. You might consider the 9s12 devices at some point because of their superior BDM debugging. Eric
On Apr 5, 7:12 am, "Eric" <englere_...@yahoo.com> wrote:
> On Apr 4, 9:56 am, "Mr Dump" <dth42...@bigpond.net.au> wrote: > > > The gist of it is: I load numbers into registers and then jump to a > > subroutine, i check the numbers before and after the jump, but they > > have changed- any clues to what is happening? > > Is an interrupt occuring? > > When you say "registers", do you mean MCU registers or I/O control > registers? > > Buffalo is not a very good way to debug since it is invasive. You > might consider the 9s12 devices at some point because of their > superior BDM debugging. > > Eric
Hi Eric, Thanks for responding! by registers, I mean MCU registers, Reg X and Reg B. Im using Buffalo, could the buffalo BR command be a cause?- i'm using that to halt things to look at the registers. I thought for a while I might have been using direct addressing by accident instead of load immediate, but the check before the jump subroutine command shows the number I want, but the check immediately after the jump shows a change! It is weird, the code works when loaded into ram, but I needed it put in EEPROM, so I changed address labels around to suit etc.... and partial operation occurs, but not quite what I want, and it seems to be at this jump point, that things are going amiss. cheers,
On Apr 6, 12:23 pm, "Mr Dump" <dth42...@bigpond.net.au> wrote:
BWAHHHH!!  He he he found it- it's NOT changing the registers at
all!!!
The same routine is called for earlier in the initialisation setup- so
when the break point exited,
I was looking at *those* values!  It pays to have a nights sleep on
the matter!
Thanks Eric for your time!
[SNIP]