📄 lcddriver1.s
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AREA BOOTROM, CODE, READONLY
PIO_BASE EQU 0xFFFF0000
PIO_PDSR EQU 0xFFFF003C
;XXXX 0000
;E(1),R/~W,RS(1 data,0 commmand)
LCD_CW_E EQU 0x80
;100 X
LCD_CR_E EQU 0xC0
;110 X
LCD_DW_E EQU 0xA0
;101 X
LCD_DR_E EQU 0xE0
;111 X
;write to cs4
LCD_CW EQU 0x00
;000 X
LCD_CR EQU 0x40
;010 X
LCD_DW EQU 0x20
;001 X
LCD_DR EQU 0x60
;011 X
;write to cs4
LCDx_y EQU 0x00000F00
CS4_addr EQU 0x40000000
;r6 command ,r7 data
;r5 CS4
P0_P7MASK EQU 0xFFFFFF00
ENTRY
delay2ms
STMFD sp!,{r0,lr}
ldr r0, =0x00013880
dly2ms
sub r0,r0,#1
bne dly2ms
LDMFD sp!,{r0,PC};Return
delay600ns
STMFD sp!,{lr}
;>=600ns is ok
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
LDMFD sp!,{PC};Return
R0_readP0_P7
STMFD sp!,{r2,lr}
LDR R2,=PIO_PDSR
LDR R0,[R2]
BIC R0,R0,#0xFFFFFF00
LDMFD sp!,{r2,PC};Return
R0_writeP0_P7
STMFD sp!,{r1-r3,lr}
;R0 LOW 8-BIT => PIO0-PIO7
;SET R0 BEFORE CALL
LDR R1,=PIO_BASE
LDR R3,=P0_P7MASK
MOV R2,R0;backup r0
BIC R2,R2,R3
STR R2,[R1,#0x30];SET OUTPUT DATA REGISTER
MVN R2,R0
BIC R2,R2,R3
STR R2,[R1,#0x34];CLEAR OUTPUT DATA REGISTER
LDMFD sp!,{r1-r3,PC};Return
LCD_CommandWrite
STMFD sp!,{r0-r1,lr}
;写指令,r7
;>=140ns? or delay450ns=>600ns
ldrb r0,=LCD_CW_E
ldr r1,=CS4_addr
strb r0,[R1]
mov r0,r7
bl R0_writeP0_P7
bl delay600ns
;write,close E
ldrb r0,=LCD_CW
strb r0,[R1]
bl delay600ns
LDMFD sp!,{r0-r1,PC};Return
LCD_CommandRead
STMFD sp!,{r0-r1,lr}
;读指令
;读BF到C
;读AC到r6 low 8 bit
;>=140ns? or delay450ns=>600ns
ldrb r0,=LCD_CR_E
ldr r1,=CS4_addr
strb r0,[R1]
bl delay600ns
;read,close E
bl R0_readP0_P7
mov r6,r0
mov r0,r0,ror #8;BF to C flag
ldrb r0,=LCD_CR
strb r0,[R1]
bl delay600ns
LDMFD sp!,{r0-r1,PC};Return
LCD_DataRead
STMFD sp!,{r0-r1,lr}
;读数据，R6
;>=140ns? or delay450ns=>600ns
ldrb r0,=LCD_DR_E
ldr r1,=CS4_addr
strb r0,[R1]
bl delay600ns
;read,close E
bl R0_readP0_P7
mov r6,r0
ldrb r0,=LCD_DR
strb r0,[R1]
bl delay600ns
LDMFD sp!,{r0-r1,PC};Return
LCD_DataWrite
STMFD sp!,{r0-r1,lr}
;写数据,r7
;>=140ns? or delay450ns=>600ns
ldrb r0,=LCD_DW_E
ldr r1,=CS4_addr
strb r0,[R1]
mov r0,r7
bl R0_writeP0_P7
bl delay600ns
;write,close E
ldrb r0,=LCD_DW
strb r0,[R1]
bl delay600ns
LDMFD sp!,{r0-r1,PC};Return
PR1 STMFD sp!,{lr}
;写指令
;preset R7
PR11
bl LCD_CommandRead
bcs PR11
bl LCD_CommandWrite
LDMFD sp!,{PC};Return
PR2 STMFD sp!,{lr}
;写显示数据,
;preset r7
PR21
bl LCD_CommandRead
bcs PR21
bl LCD_DataWrite
LDMFD sp!,{PC};Return
PR3 STMFD sp!,{lr}
;读显示数据，r6
PR31
bl LCD_CommandRead
bcs PR31
bl LCD_DataRead
LDMFD sp!,{PC};Return
INITLCD STMFD sp!,{R7,lr}
;LCD初始化设置子程序
ldr r7,=0x00000030
bl PR1
bl delay2ms
ldr r7,=0x00000030
bl PR1
bl delay2ms
ldr r7,=0x00000030
bl PR1
bl delay2ms
ldr r7,=0x00000038
bl PR1;设置工作方式
ldr r7,=0x00000001
bl PR1;清屏
ldr r7,=0x00000006
bl PR1;设置输入方式
ldr r7,=0x00000000F
bl PR1;设置显示方式
ldrb r7,=0x80
bl PR1
LDMFD sp!,{R7,PC};Return
DISPLAY_CHAR STMFD sp!,{r1,R7,lr}
;hex to char
;WRITE R3 LOW 4 BIT BEFORE CALL
;R3 LOW 4-BIT
LDR R1,=hex_to_char_tab;hex->char
LDRB R7,[R1,R3]
bl PR2
bl delay2ms
LDMFD sp!,{r1,R7,PC};Return
DISPLAY_R0 STMFD sp!,{R1-R3,lr}
;DISPLAY R0
;WRITE R0 BEFORE
LDR R2,=0x1C;右移位数
LDR R1,=0x0FFFFFFF
DIS_R0_LOOP
BIC R3,R0,R1
MOV R3,R3,LSR R2
BL DISPLAY_CHAR;
CMP R2,#0
BEQ DIS_R0_END
MOV R1,R1,ROR #4
SUB R2,R2,#4
B DIS_R0_LOOP
DIS_R0_END
LDMFD sp!,{R1-R3,PC};Return
DISPLAYRAM STMFD sp!,{R0-R2,lr}
;r1 start addr
; LDR R1,=0x02000000;START ADDRESS TO DISPLAY
;以0xFFFFFFFF结尾
SUB R1,R1,#4
LDR R2,=0xFFFFFFFF;END OF DISP
DISPRAMLOOP LDR R0,[R1,#4]!
CMP R0,R2
BEQ DISPRAMEND
BL DISPLAY_R0
B DISPRAMLOOP
DISPRAMEND
LDMFD sp!,{R0-R2,PC};Return
WRIstring STMFD sp!,{r0,r7,lr}
;正常显示字符串，以0x00结尾
;入口:r5=字符串首地址!
LDR R0,=0x0;COUNT
WRIachar LDRB R7,[R5,R0]
CMP R7,#0
BEQ WRIstrend
BL PR2
ADD R0,R0,#1
B WRIachar
WRIstrend LDMFD sp!,{r0,r7,pc};Return
lcd_main STMFD sp!,{r5,lr}
BL INITLCD
LDR R5,=my_wel_str
BL WRIstring
LDMFD sp!,{r5,pc};Return
my_wel_str
DCB 'W','e','l','c';"Welcome!-Happy Long"
DCB 'o','m','e','!'
DCB '-','H','a','p'
DCB 'p','y',' ','L'
DCB 'o','n','g',' '
DCD 0x00000000;C7D6 NO
hex_to_char_tab
DCB "0","1","2","3"
DCB "4","5","6","7"
DCB "8","9","A","B"
DCB "C","D","E","F"
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