PD17012_15 Datasheet, PDF (247/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
20.6.2 Reading alternate switches and diode switches
Here is a program example.
Example To read statuses of alternate and diode switches of LCD15/KS15/PYA15 to LCD8/KS8/PYA8 pins to
addresses 20H to 27H of BANK0 of data memory
KS8
KEY_IN
NIBBLE8 0.20H
MEM
0.73H
; P0D port register
KEY_LOAD:
CLR1
KSCAN:
LOOP:
SET2
MOV
MOV
MOV
MOV
MOV
MOV
MOV
MOV
PUT
SKF1
BR
PYASEL
LCDEN, KSEN
DBF3, #0000B
DBF2, #0001B
DBF1, #0000B
DBF0, #0000B
IXM, #0000B
IXL, #0000B
RPH, #0000B
RPL, #0000B
KSR, DBF
KEYJ
KCHECK
; Sets LCD15/KS15/PYA15 to LCD8/KS8/PYA8 pins
; to LCD segment
; LCD segment and key source signal output
; Sets key source data
; Outputs low level from KS8
; Outputs signal of key source data
; Determines if key input is latched
Processing A
; Waits until key input is latched
BR
KCHECK:
MOV
SET1
ST
CLR1
MOV
INC
ADD
ADD
SKT1
BR
KEY_END:
LOOP
RPL#.DM.KEY_IN SHR 3 AND 0EH
IXE
KS8, KEY_IN
; Stores key input data to data memory
IXE
RPL, #0000B
IX
DBF2, DBF2
; Updates value of key source data and
DBF3, DBF3
CY
; scans key again
; Determines if all key source lines are input
KSCAN
; End of input
Data Sheet U10101EJ4V0DS
245