SOFTWARE

6/10

6 SOFTWARE

The assembly code given below is guidance only. The complete software with all the files can

be found in the software library.

st7/

; the first line is reserved

; for specifying the instruction set

; of the target processor

;************************************************************************

; TITLE:

WAKE.ASM

; AUTHOR:

PPG Microcontroller Applications Team

; DESCRIPTION:

Main program (use of the Halt mode for decoding

;

a keypad).

;

;************************************************************************

TITLE

"WAKE.ASM"

; this title will appear on each

; page of the listing file

MOTOROLA

; this directive forces the Motorola

; format for the assembly (default)

#INCLUDE “st72251.inc”; include st72251 registers and memory mapping file

#INCLUDE “constant.inc” ; include general constants file

;***********************************************************************

;

Variables, constants defined and referenced locally

;

You can define your own values for a local reference here

;***********************************************************************

;************************************************************************

;

Public routines (defined here)

;************************************************************************

WORDS

segment 'rom'

.Init

LD

A,#$80

; interrupts are caused by falling edge (on Port C).

LD

MISCR,A

LD

A,#$0F

LD

PBDDR,A

LD

PBOR,A

; PB0 to PB3 configures as outputs(LEDS).

LD

PADDR,A

CLR PAOR

; PA0 to PA3 configured as outputs.

CLR

PADR

LD

A,#$0F