;*********************************************
;?????? Max7219 最底層調(diào)用函數(shù)
;?????????????????? UPDATA:2001.10.13
;*********************************************

??????? NAME???? DISP
?PR?CLR_DISP?DISP??? SEGMENT CODE
?PR?CSH_DISP?DISP??? SEGMENT CODE
?PR?DISP_IN1?DISP??? SEGMENT CODE
?PR?DISP_IN2?DISP?????? SEGMENT CODE
PUBLIC CLR_DISP,CSH_DISP,_DISP_IN1,_DISP_IN2
???
??? PCLK??? bit??? P1.7
??? PLD??? bit??? P1.5
??? PIN??? bit??? P1.6

;*********************************************
;?????? 函數(shù)名:??? CLR_DISP
;?????? 功? 能:??? CLEAR DISPLAY
;*********************************************
RSEG ?PR?CLR_DISP?DISP
CLR_DISP:??? MOV??? R7,#8??????????????? ;8 digits
CLR_DISP0:??? MOV??? R5,#0FH??????????????? ;blank???
??????? LCALL??? _disp_in1??????????? ;主max7219
??????? DJNZ??? R7,CLR_DISP0

??????? MOV??? R7,#8??????????????? ;8
digits
CLR_DISP1:??? MOV??? R5,#0FH??????????????? ;blank
??????? LCALL??? _disp_in2??????????? ;從max7219
??????? DJNZ??? R7,CLR_DISP1
??????? RET

;*********************************************
;??? 函數(shù)名:??? CSH_DISP
;??? 功? 能:??? 初始化7219各個寄存器
;*********************************************
RSEG ?PR?CSH_DISP?DISP
CSH_DISP:??? CLR??? PLD
??????? MOV??? R1,#50??????? ;delay 100us
??????? DJNZ??? R1,$
??????? SETB??? PLD
??????? MOV??? R1,#50
??????? DJNZ??? R1,$

;初始化主max7219各個寄存器
??????? MOV??? R7,#0CH??????? ;Shutdown
??????? MOV??? R5,#1??????? ;Normal Operation 1
??????? LCALL??? _disp_in1???

??????? MOV??? R7,#0FH??????? ;Display Test
??????? MOV??? R5,#01H??????? ;1: display 8.
??????? LCALL?? _disp_in1

??????? MOV??? R1,#50
??????? DJNZ??? R1,$

??????? MOV??? R7,#09H??????? ;Decode-Mode
??????? MOV??? R5,#0FFH??? ;8 digits Code B Font
??????? LCALL?? _disp_in1

??????? MOV??? R7,#0AH??????? ;REGISTER:Intensity
??????? MOV??? R5,#9??????? ;Format:DUTY CYCLE 19/32
??????? LCALL??? _disp_in1

??????? MOV??? R7,#0BH??????? ;REGISTER:Scan Limit
??????? MOV??? R5,#07H??????? ;Format:Display didits 0-7
??????? LCALL??? _disp_in1

??????? MOV??? R7,#0FH??????? ;Display Test
??????? MOV??? R5,#00H??????? ;0: Normal Operation
??????? LCALL?? _disp_in1

??????? CLR???? PLD
??????? MOV??? R1,#50
??????? DJNZ??? R1,$
??????? SETB??? PLD
??????? MOV??? R1,#50
??????? DJNZ??? R1,$

;初始化從max7219各個寄存器
;命令字和格式同上

??????? MOV??? R7,#0CH
??????? MOV??? R5,#01H???????
??????? LCALL?? _disp_in2

??????? MOV??? R7,#0FH
??????? MOV??? R5,#01H
??????? LCALL?? _disp_in2

??????? MOV??? R1,#50
??????? DJNZ??? R1,$

??????? MOV??? R7,#09H
??????? MOV??? R5,#0FFH
??????? LCALL?? _disp_in2

??????? MOV??? R7,#0AH
??????? MOV??? R5,#9
??????? LCALL?? _disp_in2

??????? MOV??? R7,#0BH
??????? MOV??? R5,#07H???????
??????? LCALL?? _disp_in2

??????? MOV??? R7,#0FH
??????? MOV??? R5,#00H
??????? LCALL?? _disp_in2

??????? RET

;*********************************************
;??? 函數(shù)名:??? _disp_in1
;??? 功? 能:??? 將16位數(shù)據(jù)送入主max7219寄存器
;??? 輸? 入: R7 寄存器,地址
;?????????????? R5 寄存器,數(shù)據(jù)
;*********************************************
RSEG ?PR?disp_in1?DISP
_disp_in1:????? CLR???? PLD???????????? ;LOAD=0

??????? MOV??? R6,#16
??????? MOV??? A,#0
DIN_LP0:??? CLR??? PCLK
??????? RLC??? A??????? ;帶進位C的循環(huán)
??????? MOV??? PIN,C
??????? SETB??? PCLK
??????? DJNZ??? R6,DIN_LP0
;通過16個CLK,將16個0通過DOUT送入從max7219的DIN
;也可以不需要這16個循環(huán)，只是為了同從max7219的程序區(qū)別起見

??????? MOV??? R6,#8
??????? MOV??? A,R7??????? ;將第一個字節(jié)的8位送入
DIN_LP1:??? CLR??? PCLK??????? ;寄存器,地址
??????? RLC??? A
??????? MOV??? PIN,C
??????? SETB??? PCLK
??????? DJNZ??? R6,DIN_LP1
???????
??????? MOV??? R6,#8
??????? MOV??? A,R5??????? ;將第二個字節(jié)的8位送入
DIN_LP2:??? CLR??? PCLK??????? ;寄存器,數(shù)據(jù)
??????? RLC??? A
??????? MOV??? PIN,C
??????? SETB??? PCLK
??????? DJNZ??? R6,DIN_LP2

??????????????? SETB??? PLD???????????? ;LOAD 上升沿
??????? RET

;*********************************************
;??? 函數(shù)名:??? _disp_in2
;??? 功? 能:??? 將16位數(shù)據(jù)送入從max7219寄存器
;??? 輸? 入: R7 寄存器,地址
;?????????????? R5 寄存器,數(shù)據(jù)
;*********************************************
RSEG ?PR?disp_in2?DISP
_DISP_IN2:??? CLR???? PLD

??????? MOV???? R6,#08H
??????? MOV???? A,R7??????? ;R7 第一個字節(jié)8位
DIN_LP3:??????? CLR???? PCLK
??????? RLC???? A
??????? MOV???? PIN,C
??????? SETB??? PCLK
??????? DJNZ??? R6,DIN_LP3

??????? MOV???? R6,#08H
??????? MOV???? A,R5??????? ;R5 第二個字節(jié)8位
DIN_LP4:??????? CLR???? PCLK
??????? RLC???? A
??????? MOV???? PIN,C
??????? SETB??? PCLK
??????? DJNZ??? R6,DIN_LP4

??????? MOV??? R6,#16