; ********************************************
; Function :       4X4按键,数码管显示程序    *

; MicroProcessor : HT48R50A-1/28SKDIP-A      *

; Author:         www.picavr.com             *
; Crystal :       4MHz                       *
; ********************************************
#INCLUDE                HT48R50A-1.INC
;---------------------------------------------
DATA    .SECTION        AT 60H  'DATA'
DISPLAY_DATA            DB      ?       ;[60H]
DISPLAY_COUNTER         DB      ?       ;[61H]
SCAN_COUNTER            DB      ?       ;[62H]
SCAN_DATA               DB      ?       ;[63H]
SCAN_CODE               DB      ?       ;[64H]
;---------------------------------------------
CODE    .SECTION        AT 00H  'CODE'
        ORG     00H
        JMP     START
START:
        MOV     A,0FH
        MOV     PAC,A
        SET     PA
        CLR     PBC
        CLR     PB
SCAN_BEGIN:
        MOV     A,04H
        MOV     SCAN_COUNTER,A
        MOV     A,70H
        MOV     SCAN_DATA,A
SCAN_NEXT:
        MOV     PA,A
        CALL    KEY_IN
        SET     C
        RRC     SCAN_DATA
        MOV     A,SCAN_DATA
        AND     A,0F0H
        SDZ     SCAN_COUNTER
        JMP     SCAN_NEXT
        JMP     SCAN_BEGIN
        RET
;---------------------------------------------
; 4x4 Keyboard code
        ORG     0E00H
        DC      077H,07BH,07DH,07EH     ;0123
        DC      0B7H,0BBH,0BDH,0BEH     ;4567
        DC      0D7H,0DBH,0DDH,0DEH     ;89AB
        DC      0E7H,0EBH,0EDH,0EEH     ;CDEF

KEY_IN  PROC
        CLR     TBLP
        MOV     A,10H
        MOV     DISPLAY_COUNTER,A
SCAN_KEY:
        TABRDL  DISPLAY_DATA
        TABRDC  SCAN_CODE
        INC     TBLP
        MOV     A,PA
        SUB     A,SCAN_CODE
        SZ      ACC
        JMP     NEXT_CODE
        MOV     A,DISPLAY_DATA
        MOV     PB,A
KEY_STATUS:
        MOV     A,PA
        AND     A,0FH
        XOR     A,0FH
        SZ      ACC
        JMP     KEY_STATUS
        JMP     OVER
NEXT_CODE:
        SDZ     DISPLAY_COUNTER
        JMP     SCAN_KEY
OVER:
        RET
KEY_IN  ENDP
;---------------------------------------------
; 7-Segment(Common andoe) display code
        ORG     0F00H
        DC      081H,0CFH,092H,086H     ;0123
        DC      0CCH,0A4H,0A0H,08FH     ;4567
        DC      080H,084H,088H,0E0H     ;89AB
        DC      0B1H,0C2H,0B0H,0B8H     ;CDEF
;---------------------------------------------
        END