In SX Microcontrollers, SX/B Compiler and SX-Key Tool, ringlord wrote:

All--

 

While I'm waiting on other developments, I decided to try to cut a little SX assember code. The last assember I used was either for the 8080 or Z80 instruction set. This was a long time ago.

 

In any case, I was rather amazed at how the rudiments returned to me! All the code listed below does is blink and LED and call a subroutine for the pause. The environment is a PDB with one of [b]RobotWorkshop's[/b] SX48 modules, a USB SX-Key Rev. B and the SX-Key v3.3.0 IDE.

 

If you have time to look at the code, I would appreciate comments. I would PARTICULARLY like to learn how to time instructions so I could write a good delay routine, instead of empirically figuring it out. Plus, I am sure the code could be shortened a bunch. I would really like to see how one might do that. (It would be neat if I knew how to make these little code segments look neat in a post like everyone else does, too.)

 

Thanks!

 




; Program name: 01-16-10 SX48 First Assembly Code.SRC
;
; Author: Bill Chennault
;
; Date: 01/16/10
;
; Description: This program blinks an LED and uses a subroutine for delay 

device  sx48,oschs3
IRC_CAL  IRC_SLOW
reset  start_point
freq  50_000_000 

org  0   ; place assembled code beginning at address 0 

start_point  

Main
  mov  !rb,#0  ; make port B pins all output
  mov rb,#0  ; make all port B pins high (turn LED on) 

  call Delay  ; pause 

  mov rb,#1  ; make all port B pins low (turn LED off) 

  call  Delay  ; delay 

  jmp Main  ; do this forever 

; subroutine: Delay 

Delay  mov $0f,#$ff ; set fr 0fh to ffh
  mov $10,#$ff ; set fr 10h to ffh
  mov $11,#$14 ; set fr 11h to 14h
pause  decsz $0f  ; decrement fr 0fh; if 0, skip the next instruction
  jmp pause  ; it wasn't 0, stay in the loop
  decsz $10  ; decrement fr 10h; if 0, skip the next instruction
  jmp pause  ; it wasn't 0, stay in the loop
  decsz $11  ; decrement fr 101; if 0, skip the next instruction
  jmp pause  ; it wasn't 0, stay in the loop
 
  ret 

jmp start_point 
[/quote]


--Bill

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