AN1833 Freescale Semiconductor / Motorola, AN1833 Datasheet - Page 36

• Manufacturer Part Number: AN1833
• Description: A Low-Power Wireless Remote Control Transmitter and Receiver
• Manufacturer: Freescale Semiconductor / Motorola

Application Note
KeyPad030:
KeyPad035:
KeyPad040
KeyPad_Table:
KeyPad_Table_Top
************************************************************************************
#INCLUDE 'H705J1A.FRK'
************************************************************************************
36
decx
decx
bpl
ldx
bra
lda
tax
lda
and
sta
txa
tsta
rts
org
fcb
KeyPad010
#$00
KeyPad035
KeyPad_Table+2,x
portb
#$F0
portb
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
MOR
Freescale Semiconductor, Inc.
06
For More Information On This Product,
;Table of keypad decode values and codes.
;Fill in your own key codes. Codes must be 1
; byte each. Currently row 1 col 1 = 0, which
; duplicates no key found. This is a result
; of limiting the codes to 4 bits for display
; on PA[4..7]
$01,$01,$F1
$01,$02,$F2
$01,$04,$F3
$01,$08,$FA
$02,$01,$F4
$02,$02,$F5
$02,$04,$F6
$02,$08,$FB
$04,$01,$F7
$04,$02,$F8
$04,$04,$F9
$04,$08,$FC
$08,$01,$FF
$08,$02,$FE
$08,$04,$FF
$08,$08,$FD
Go to: www.freescale.com
;Include the equates for the HC705J1A
; next value in table
;If not below bottom of table
; try again.
;A key was not decoded, so:
;Return with null character
;Load key code into Acc.
;Store in X for now.
;'Help' the pulldowns by driving the
; lines low. This minimizes current
; draw while debouncing.
;Get result back to Acc
;Set the flags so calling routine
; can use them for decisions.
;Return with result value in Acc
; Row
; PA0
; PA0
; PA0
; PA0
; PA1
; PA1
; PA1
; PA1
; PA2
; PA2
; PA2
; PA2
; PA3
; PA3
; PA3
; PA3
;Enable Port A Interrupts
;If used on a mask rom part,
; be sure to specify this option.
;Enable level sensitivity on IRQs
; SOSCD = Short Oscillator delay
; enable
Column
PB0
PB1
PB2
PB3
PB0
PB1
PB2
PB3
PB0
PB1
PB2
PB3
PB0
PB1
PB2
PB3
MOTOROLA
AN1833