gnupic: gpsim register question
Subject:
Re: gpsim register question
From:
"Maxim Wexler" ####@####.####
Date:
30 Dec 2006 18:50:24 +0000
Message-Id: <a0811460612301050k7e33dadcpa4aa0a59af19a655@mail.gmail.com>
aargh, did it again! Confusing the tab with the caps lock 8(
Anyway
COUNT1 equ 20h
Now when I step through the code and pass the decfsz command 20h in the
register viewer fills up with FFh from 00h.
Where does that 255 come from? There's no mention anywhere in the previous
code. And besides, according to the pdf for DECFZ f,d f can't be more that
127.
Here's the code up to the first(of two) delay loops:
;*****Set up the Constants****
STATUS equ 03h ;Address of the STATUS register
TRISA equ 85h ;Address of the tristate register for port A
PORTA equ 05h ;Address of Port A
COUNT1 equ 20h ;First counter for our delay loops
COUNT2 equ 21h ;Second counter for our delay loops
;****Set up the port****
bsf STATUS,5 ;Switch to Bank 1
movlw 00h ;Set the Port A pins
movwf TRISA ;to output.
bcf STATUS,5 ;switch back to Bank 0
movlw 02h ;Set up our w register with 02h
;****Turn the LED on and off****
Start xorwf PORTA,1 ;Toggle the LED
;****Add a delay
call Delay
;****Now go back to the start of the program
goto Start ;go back to Start and turn LED on again
;****Here is our Subroutine
Delay
Loop1 decfsz COUNT1,1 ;This second loop keeps the LED
goto Loop1 ;turned off long enough for us to
<...>
Another thing: In the breadboard window only porta0 to porta5 become
outputs. 6&7 remain inputs. Why, after being sent all zeros?
Maxim
