Songhan MCU 1602

//{{SONIX_CODE_OPTION
 .Code_Option WDT_CLK Flosc/4
 .Code_Option Reset_Pin P04
 .Code_Option LVD LVD_Max ; 3.3V Reset
 .Code_Option Watch_Dog Disable ;Turn off the
 watchdog.Code_Option Low_Fcpu Flosc/1
 .Code_Option High_Clk IHRC_16M ; Internal 16M RC Oscillator
 .Code_Option High_Fcpu Fhosc/1
 .Code_Option Security Enable
 .Code_Option Noise_Filter Enable
//}}SONIX_CODE_OPTION
 DATA EQU P4 ;Data port
 DATAM EQU P4M
 
 RS EQU P0.0 ;Data/command
 RSM EQU P0M.0
 
 RW EQU P0.1 ;Read/write
 RWM EQU P0M.1
 EEQU P0.2 ; Control enable
 EM EQU P0M.2

 ORG 0000H
 JMP A1
 ORG 0015H
A1: MOV A,#30H;Display content
 MOV 41H,A
 MOV A,#31H
 MOV 42H,A
 MOV A,#32H
 MOV 43H,A
 MOV A,#33H
 MOV 44H,A
 
 MOV A,#01H;Clear screen
 MOV 30H,A
 CALL ZL01
 MOV A,#250
 MOV 31H,A
A2: 
 MOV A,#38H;Set display mode 5*7 dots
 MOV 30H,A
 CALL ZL01
 DECMS 31H
 JMP A2
 
 MOV A,#0CH;Turn on display and turn off cursor
 MOV 30H,A
 CALL ZL01
 
 CALL XS01;Display subroutine
 
 JMP $
;****************************************************
;Display subroutine
;*************************************************  
XS01: MOV A,#38H;Set display mode
 MOV 30H,A 
 CALL ZL01
 MOV A,#0CH;Turn on display
 MOV 30H,A
 CALL ZL01
 MOV A,#0C8H;Display starting position
 MOV 30H,A
 CALL ZL01
 
 B0MOV H,#0 ; Clear "H" to address RAM bank 0.
 B0MOV L,#41H ; Set register address.
XS02: MOV A,@HL;Display content processing
 MOV 30H,A
 CALL SJ01
 INCMS L;Display next data
 MOV A,L
 CMPRS A,#45H;Is the display completed?
 JMP XS02
 RET
;********************************************
;Write command subroutine
;********************************************    
ZL01: MOV A,#0FFH;Set the data port to output state
 MOV DATAM,A
 MOV DATA,A;Output high level
 
 B0BSET RSM;Set to data mode
 B0BCLR RS
 
 B0BSET RWM;Set to read mode
 B0BSET RW
 
 B0BSET EM;Allow operation
 B0BSET E
ZL02:
 B0BCLR P4M.7;Busy check
 B0BTS0 P4.7;P4.7=1 busy, P4.7=0 idle
 JMP ZL02
 B0BSET EM;Turn off enable
 B0BCLR E
 
 B0BSET RSM; Set to command mode
 B0BCLR RS
 
 B0BSET RWM; Set to write mode
 B0BCLR RW
 
 MOV A,#0FFH; Output the content to be written to the data port
 MOV DATAM,A
 MOV A,30H
 MOV DATA,A
 
 B0BSET EM; Allow the enable operation
 B0BSET E
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 B0BSET EM; Turn off enable
 B0BCLR E
 
 RET
;********************************************
; Write data subroutine
;****************************************
SJ01: MOV A,#0FFH
 MOV DATAM,A
 MOV DATA,A
 
 B0BSET RSM
 B0BCLR RS
 
 B0BSET RWM
 B0BSET RW
 
 B0BSET EM
 B0BSET E
SJ02:
 B0BCLR P4M.7
 B0BTS0 P4.7
 JMP SJ02
 
 B0BSET EM
 B0BCLR E
 
 B0BSET RSM; Set to data mode
 B0BSET RS
 
 B0BSET RWM
 B0BCLR RW
 MOV A,#0FFH
 MOV DATAM,A
 MOV A,30H
 MOV DATA,A
 
 B0BSET EM
 B0BSET E
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 NOP
 B0BSET EM
 B0BCLR E
 
 RET
 ENDP