掌機 - FC3000 - 找出LCD初始化資料

目前量測出來的腳位

基本上，可以使用如下幾種方式，把屏的初始化資料找出來：
1. 使用J-Link Debug官方韌體程式
2. 使用QEMU跑官方韌體程式，然後把存取暫存器的內容Dump出來
3. 使用邏輯分析儀

雖然第一種方式是司徒覺得最好的方式，可惜那個山寨J-Link在Debug官方韌體程式時，常常跑飛，所以目前只能先放棄第一種方式，至於第二種方式，看似簡單，不過需要花一些時間，雖然司徒在最新版QEMU有找到支援Orangipc-PC開發板(Allwinner H3)，不過要改成F1C100S還是需要一點點時間，所以司徒接下來想測試一下邏輯分析儀的部份，不過司徒手上剛好沒有專用的邏輯分析儀，因此，司徒想使用芒果派F1C200S來當作分析儀使用，於是開始製作過程

括除焊點


勇敢的芒果派站了出來


腳位

跳線



測試程式

    .global _start
      
    .equiv CCU_BASE,              0x01c20000
    .equiv GPIO_BASE,             0x01c20800
    .equiv UART1_BASE,            0x01c25400
 
    .equiv PLL_PERIPH_CTRL_REG,   0x0028
    .equiv AHB_APB_HCLKC_CFG_REG, 0x0054
    .equiv BUS_CLK_GATING_REG2,   0x0068
    .equiv BUS_SOFT_RST_REG2,     0x02d0
    
    .equiv PA,                    (0x24 * 0)
    .equiv PB,                    (0x24 * 1)
    .equiv PC,                    (0x24 * 2)
    .equiv PD,                    (0x24 * 3)
    .equiv PE,                    (0x24 * 4)

    .equiv PORT_CFG0,             0x00
    .equiv PORT_CFG1,             0x04
    .equiv PORT_CFG2,             0x08
    .equiv PORT_DATA,             0x10
    .equiv PORT_PUL0,             0x1c
    .equiv PORT_PUL1,             0x20

    .equiv UART_RBR,              0x00
    .equiv UART_DLL,              0x00
    .equiv UART_DLH,              0x04
    .equiv UART_IER,              0x04
    .equiv UART_IIR,              0x08
    .equiv UART_LCR,              0x0c
    .equiv UART_MCR,              0x10
    .equiv UART_USR,              0x7c
 
    .arm
    .text
_start:
    .long 0xea000016
    .byte 'e', 'G', 'O', 'N', '.', 'B', 'T', '0'
    .long 0, __spl_size
    .byte 'S', 'P', 'L', 2
    .long 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
     
_vector:
    b reset
    b .
    b .
    b .
    b .
    b .
    b .
    b .

reset:
    ldr r0, =CCU_BASE
    ldr r1, =0x80041800
    str r1, [r0, #PLL_PERIPH_CTRL_REG]
    ldr r1, =0x00003180
    str r1, [r0, #AHB_APB_HCLKC_CFG_REG]

    ldr r4, =GPIO_BASE
    mov r1, #0x00000000
    str r1, [r4, #(PA + PORT_CFG0)]
    str r1, [r4, #(PC + PORT_CFG0)]
    str r1, [r4, #(PD + PORT_CFG0)]
    str r1, [r4, #(PD + PORT_CFG1)]
    str r1, [r4, #(PE + PORT_CFG0)]
    str r1, [r4, #(PE + PORT_CFG1)]
    ldr r1, =0x55555555
    str r1, [r4, #(PD + PORT_PUL0)]
    str r1, [r4, #(PD + PORT_PUL1)]
    str r1, [r4, #(PE + PORT_PUL0)]
    str r1, [r4, #(PE + PORT_PUL1)]

    ldr r5, =0x4000
    ldr r6, =64

    mov r1, #0
    mov r2, r5
    mov r3, r6
0:
    str r1, [r2]
    add r2, #4
    subs r3, #4
    bne 0b

    ldr r4, =GPIO_BASE
0:
    ldr r1, [r4, #(PD + PORT_DATA)]
    ands r1, #(1 << 0)
    bne 0b

    mov r1, #0
    ldr r2, [r4, #(PD + PORT_DATA)]
    and r2, #(1 << 12)
    lsl r2, #20
    orr r1, r2
    ldr r2, [r4, #(PA + PORT_DATA)]
    and r2, #0x07
    lsl r2, #12
    orr r1, r2
    ldr r2, [r4, #(PE + PORT_DATA)]
    ldr r3, =0x7ff
    and r2, r3
    orr r1, r2
    str r1, [r5]
1:
    ldr r1, [r4, #(PD + PORT_DATA)]
    ands r1, #(1 << 0)
    beq 1b

    add r5, #4
    subs r6, #4
    bne 0b
 
    bl uart_init
    
    ldr r0, =0x11223344
    bl uart_4byte

    ldr r5, =0x4000
    ldr r6, =64
0:
    ldr r0, [r5]
    bl uart_4byte

    ldr r0, =0xaa
    bl uart_byte

    add r5, #4
    subs r6, #4
    bne 0b
    b .
 
uart_init:
    push {r4, lr}
    ldr r4, =CCU_BASE
    ldr r1, =(1 << 21)
    str r1, [r4, #BUS_CLK_GATING_REG2]
    str r1, [r4, #BUS_SOFT_RST_REG2]
    
    ldr r4, =GPIO_BASE
    ldr r1, =0x5500
    str r1, [r4, #(PA + PORT_CFG0)]

    ldr r4, =UART1_BASE
    ldr r1, =0x00
    str r1, [r4, #UART_IER]
    ldr r1, =0xf7
    str r1, [r4, #UART_IIR]
    ldr r1, =0x00
    str r1, [r4, #UART_MCR]
    ldr r1, [r4, #UART_LCR]
    orr r1, #(1 << 7)
    str r1, [r4, #UART_LCR]
    ldr r1, =54
    str r1, [r4, #UART_DLL]
    ldr r1, =0x00
    str r1, [r4, #UART_DLH]
    ldr r1, [r4, #UART_LCR]
    bic r1, #(1 << 7)
    str r1, [r4, #UART_LCR]
    ldr r1, [r4, #UART_LCR]
    bic r1, #0x1f
    orr r1, #0x03
    str r1, [r4, #UART_LCR]
    pop {r4, pc}
    
uart_byte:
    push {r4, lr}
    ldr r4, =UART1_BASE
1:
    ldr r1, [r4, #UART_USR]
    tst r1, #(1 << 1)
    beq 1b
    strb r0, [r4, #UART_RBR]
    pop {r4, pc}

uart_4byte:
    push {r4, lr}
    mov r4, r0
    lsr r0, #24
    bl uart_byte
    
    mov r0, r4
    lsr r0, #16
    bl uart_byte
    
    mov r0, r4
    lsr r0, #8
    bl uart_byte
    
    mov r0, r4
    bl uart_byte
    pop {r4, pc}
    .end

P.S. PA3先拔除

但是詭異的事情發生了，每次量測到的資料竟然都不一樣


於是，司徒寫了一個GPIO Toggle量測


F1C200S I/O速度只有2.8MHz


屏的LCD_WR速度則是4.7MHz，難怪取出來的資料每次都不一樣，因為，最低取樣頻率至少要是原生的兩倍...，不過，司徒突然對STM32的GPIO 50MHz相當感興趣，哈


接著司徒打算使用STM32F103來做邏輯分析儀，因為官方文件說，I/O Toggle可以達到18MHz，如果再超頻，那應該是夠用，因此，司徒找來STM32F103開發板


PLL 72MHz，可以達到12MHz


PLL 128MHz，可以達到21MHz


值得注意的是，使用eor指令做I/O Toggle時，速度比str指令來的慢，只有12MHz(PLL 128MHz)


重新跳線


接著開始測試，將LCD_WR接到PB1，經由負緣觸發中斷時，接著將PC的資料寫到RAM，讀取完64Bytes後，透過UART傳回電腦


STM32F103測試程式(PB0:LCD_RS, PB1:LCD_WR, PC:LCD_DB)

    .thumb
    .cpu cortex-m3
    .syntax unified

    .equiv NVIC_ISER0,   0xe000e100
    .equiv AFIO_EXTICR1, 0x40010008

    .equiv EXTI_IMR,     0x40010400
    .equiv EXTI_EMR,     0x40010404
    .equiv EXTI_RTSR,    0x40010408
    .equiv EXTI_FTSR,    0x4001040c
    .equiv EXTI_SWIER,   0x40010410
    .equiv EXTI_PR,      0x40010414
      
    .equiv GPIOA_CRL,    0x40010800
    .equiv GPIOA_CRH,    0x40010804
    .equiv GPIOA_IDR,    0x40010808
    .equiv GPIOA_ODR,    0x4001080c
 
    .equiv GPIOB_CRL,    0x40010c00
    .equiv GPIOB_CRH,    0x40010c04
    .equiv GPIOB_IDR,    0x40010c08
    .equiv GPIOB_ODR,    0x40010c0c
 
    .equiv GPIOC_CRL,    0x40011000
    .equiv GPIOC_CRH,    0x40011004
    .equiv GPIOC_IDR,    0x40011008
    .equiv GPIOC_ODR,    0x4001100c
 
    .equiv RCC_CR,       0x40021000
    .equiv RCC_CFGR,     0x40021004
    .equiv RCC_APB2ENR,  0x40021018
 
    .equiv FLASH_ACR,    0x40022000
 
    .equiv UART1_SR,     0x40013800
    .equiv UART1_DR,     0x40013804
    .equiv UART1_BRR,    0x40013808
    .equiv UART1_CR1,    0x4001380c
    .equiv UART1_CR2,    0x40013810
    .equiv UART1_CR3,    0x40013814
 
    .equiv STACKINIT,    0x20005000
       
    .global _start
    .section .text
 
    .org 0x0000
    .word STACKINIT
    .word _start

    .org 0x005c
    .word _exti1
    
    .org 0x0200
    .align 2
    .thumb_func
_exti1:
    push {r4, lr}
    ldrh r1, [r7]
    strh r1, [r5, #2]!
    ldrh r2, [r8]
    strh r2, [r5, #2]!

    ldr r4, =EXTI_PR
    mov r1, #(1 << 1)
    str r1, [r4]
    pop {r4, pc}

    .align 2
    .thumb_func
_start:
    bl rcc_init
    bl flash_init
    bl uart_init
    
    ldr r4, =RCC_APB2ENR
    ldr r1, [r4]
    orr r1, #(1 << 4) | (1 << 3) | (1 << 2)
    str r1, [r4]
    
    ldr r4, =GPIOB_CRL
    ldr r1, =0x88888888
    str r1, [r4]
 
    ldr r4, =GPIOB_CRH
    ldr r1, =0x88888888
    str r1, [r4]
     
    ldr r4, =GPIOC_CRL
    ldr r1, =0x88888888
    str r1, [r4]
 
    ldr r4, =GPIOC_CRH
    ldr r1, =0x88888888
    str r1, [r4]

    ldr r4, =EXTI_IMR
    ldr r1, =(1 << 1)
    str r1, [r4]

    ldr r4, =EXTI_EMR
    ldr r1, =(1 << 1)
    str r1, [r4]

    ldr r4, =EXTI_FTSR
    ldr r1, =(1 << 1)
    str r1, [r4]

    ldr r4, =AFIO_EXTICR1
    ldr r1, =(1 << 4)
    str r1, [r4]

    ldr r5, =buf
    ldr r6, =buf
    ldr r7, =GPIOB_IDR
    ldr r8, =GPIOC_IDR
    
    ldr r4, =NVIC_ISER0
    ldr r1, =(1 << 7)
    str r1, [r4]

    add r6, #(64 * 2 * 2)
0:
    cmp r5, r6
    bcc 0b
    
    ldr r4, =NVIC_ISER0
    mov r1, #0
    str r1, [r4]
    
    ldr r4, =AFIO_EXTICR1
    mov r1, #0
    str r1, [r4]

    ldr r5, =buf
    ldr r6, =64
0:
    ldrh r1, [r5, #2]!
    lsl r1, #31

    eor r0, r0
    ldrh r0, [r5, #2]!
    orr r0, r1
    bl uart_4byte

    subs r6, #1
    bne 0b

    ldr r0, =0x11223344
    bl uart_4byte
    b .

    .align 2
    .thumb_func
uart_init:
    push {r4, lr}
    ldr r4, =RCC_APB2ENR
    ldr r1, [r4]
    ldr r2, =(1 << 14) | (1 << 2) | (1 << 0)
    orr r1, r2
    str r1, [r4]
 
    ldr r4, =GPIOA_CRH
    ldr r1, [r4]
    bic r1, #0xff0
    orr r1, #0x4b0
    str r1, [r4]
 
    ldr r4, =UART1_BRR
    @ldr r1, =(39 << 4) | (1 << 0) @ 115200bps 72MHz
    ldr r1, =(69 << 4) | (7 << 0) @ 115200bps 128MHz
    str r1, [r4]
 
    ldr r4, =UART1_CR1
    ldr r1, =(1 << 13) | (1 << 3)
    str r1, [r4]
    pop {r4, pc}
 
    .align 2
    .thumb_func
uart_byte:
    push {r4, lr}
    ldr r4, =UART1_SR
0:
    ldr r1, [r4]
    tst r1, #(1 << 7)
    beq 0b
 
    ldr r4, =UART1_DR
    str r0, [r4]
    pop {r4, pc}
    
    .align 2
    .thumb_func
uart_4byte:
    push {r4, lr}
    mov r4, r0
    lsr r0, #24
    bl uart_byte

    mov r0, r4
    lsr r0, #16
    bl uart_byte
    
    mov r0, r4
    lsr r0, #8
    bl uart_byte
    
    mov r0, r4
    bl uart_byte
    pop {r4, pc}
     
    .align 2
    .thumb_func
rcc_init:
    push {r4, lr}
    ldr r4, =RCC_CR
    ldr r1, =(1 << 26) | (1 << 16)
    str r1, [r4]
0:
    ldr r1, [r4]
    tst r1, #(1 << 17)
    bne 0b
 
    ldr r4, =RCC_CFGR
    @mov r1, #(7 << 18) @ 72MHz
    mov r1, #(14 << 18) @ 128MHz
    orr r1, #(1 << 16)
    str r1, [r4]
 
    ldr r4, =RCC_CR
    ldr r1, [r4]
    orr r1, #(1 << 24)
    str r1, [r4]
0:
    ldr r1, [r4]
    tst r1, #(1 << 25)
    bne 0b
 
    ldr r4, =RCC_CFGR
    ldr r1, [r4]
    orr r1, #2
    str r1, [r4]
0:
    ldr r1, [r4]
    tst r1, #(1 << 3)
    bne 0b
    pop {r4, pc}
 
    .align 2
    .thumb_func
flash_init:
    push {r4, lr}
    ldr r4, =FLASH_ACR
    mov r1, #0x32
    str r1, [r4]
    pop {r4, pc}

    .data
    .align 2
buf: .skip (64 * 2 * 2)
    .end

測試後發現，資料還是會有不一致的狀況，因此，STM32F103目前無法勝任這個任務...

接著，司徒為了確定LCD輸出代碼是否有問題，因此，測試了一下Miyoo，確實是可以動作的


Q8掌機也是沒有問題


不過，將屏拿到Q8掌機測試，結果還是點不亮，共測試GC9300、GC9306、ST7789、HX8357C、R61520初始化程式，還是不行...


於是，司徒買一台山寨Saleae Logic 16，體積很迷你


不過，同時開啟16通道時，取樣率只有16MS/s...


在測試過16通道16MS/s取樣率後，司徒發現每次取的資料都有變動，資料不一致性有點大，這邏輯分析儀...，於是，司徒改成使用12通道25MS/s的取樣率


測試幾次後，發現資料不一致性還是有，不過已經好很多了，不過LCD是16Bits，在加上LCD_WR、LCD_RS，需要18通道才行，於是司徒分兩次擷取
低位元資料(取5次)：LCD_RS、LCD_WR、LCD_DB0~LCD_DB9
高位元資料(取5次)：LCD_RS、LCD_WR、LCD_DB6~LCD_DB15


擷取後，把高位元資料進行排列，假定這些多餘的資料為雜訊，手動濾掉


低位元資料進行排列，假定這些多餘的資料為雜訊，手動濾掉


再做合併時，發現低位元資料少一筆，這...，不過，仔細一看，資料都是一筆CMD、一筆DAT，然後LCD_DB6~LCD_DB9是疊加取樣，因此，交叉比對後，發現第一筆高位元資料是雜訊


合併後的初始化命令

CMD:0x800
DAT:0x100
CMD:0x1000
DAT:0x700
CMD:0x1800
DAT:0xc002
CMD:0x2000
DAT:0x0
CMD:0x4000
DAT:0x1200
CMD:0x4800
DAT:0x0
CMD:0x5000
DAT:0x0
CMD:0x6000
DAT:0x0
CMD:0x6800
DAT:0x0
CMD:0x7800
DAT:0x0
CMD:0x8000
DAT:0x0
CMD:0x8800
DAT:0x3800
CMD:0x9000
DAT:0x0
CMD:0x9800
DAT:0x0
CMD:0x3800
DAT:0x800
CMD:0x8000
DAT:0x8682
CMD:0x8800
DAT:0x3e60
CMD:0x9000
DAT:0xc080
CMD:0x9800
DAT:0x603
CMD:0x4820
DAT:0xf000
CMD:0x5820
DAT:0x7000
CMD:0x20
DAT:0x0
CMD:0x820
DAT:0x0
CMD:0x8020
DAT:0x0
CMD:0x8820
DAT:0x3d00
CMD:0x9020
DAT:0x2000
CMD:0xa820
DAT:0x2a00
CMD:0xb020
DAT:0x2000
CMD:0xb820
DAT:0x3b00
CMD:0xc020
DAT:0x1000
CMD:0xc820
DAT:0x3f00
CMD:0xe020
DAT:0x1500
CMD:0xe820
DAT:0x2000
CMD:0x8040
DAT:0x0
CMD:0x8840
DAT:0x78e0
CMD:0x9040
DAT:0x0
CMD:0x9840
DAT:0xf920
CMD:0x60
DAT:0x714
CMD:0x860
DAT:0x800
CMD:0x5060
DAT:0x0
CMD:0x80
DAT:0x0
CMD:0x880
DAT:0x0
CMD:0x1080
DAT:0x0
CMD:0x1880
DAT:0x0
CMD:0x2080
DAT:0x0
CMD:0x2880
DAT:0x0
CMD:0x8080
DAT:0x8000
CMD:0x9080
DAT:0x600
CMD:0x1800
DAT:0x4020
CMD:0x3800
DAT:0x9920
CMD:0x8040
DAT:0x0
CMD:0x8840
DAT:0x78e0
CMD:0x9040
DAT:0x0
CMD:0x9840
DAT:0xf920
CMD:0x20
DAT:0x78e0
CMD:0x820
DAT:0x0
CMD:0x1020
DAT:0x0

測試程式

    .global _start
    
    .equiv PIO_BASE,  0x01c20800 
    .equiv PD,        (0x24 * 3)
    .equiv PE,        (0x24 * 4)
    .equiv PIO_CFG0,  0x00
    .equiv PIO_CFG1,  0x04
    .equiv PIO_CFG2,  0x08
    .equiv PIO_DATA,  0x10

    .equiv LCD_CS,    (1 << 21)
    .equiv LCD_RD,    (1 << 20)
    .equiv LCD_RS,    (1 << 19)
    .equiv LCD_WR,    (1 << 18)
    .equiv LCD_RST,   (1 << 11)
    .equiv LCD_BL,    (1 << 6)
    
    .arm
    .text
_start:
    .long 0xea000016
    .byte 'e', 'G', 'O', 'N', '.', 'B', 'T', '0'
    .long 0, __spl_size
    .byte 'S', 'P', 'L', 2
    .long 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
     
_vector:
    b reset
    b .
    b .
    b .
    b .
    b .
    b .
    b .
     
reset:
    ldr r4, =PIO_BASE + PD
    ldr r1, =0x11111111
    str r1, [r4, #PIO_CFG0]
    str r1, [r4, #PIO_CFG1]
    ldr r1, =0x00111111
    str r1, [r4, #PIO_CFG2]

    ldr r4, =PIO_BASE + PE
    ldr r1, [r4, #PIO_CFG0]
    bic r1, #0xf000000
    orr r1, #0x1000000
    str r1, [r4, #PIO_CFG0]

    ldr r1, [r4, #PIO_CFG1]
    bic r1, #0xf000
    orr r1, #0x1000
    str r1, [r4, #PIO_CFG1]

    ldr r4, =PIO_BASE + PD
    ldr r1, =0xffffffff
    str r1, [r4, #PIO_DATA]

    ldr r4, =PIO_BASE + PE
    ldr r1, =0xffffffff
    str r1, [r4, #PIO_DATA]

    bl lcd_rst

    ldr r0, =0x800
    bl lcd_cmd

    ldr r0, =0x100
    bl lcd_dat

    ldr r0, =0x1000
    bl lcd_cmd

    ldr r0, =0x700
    bl lcd_dat

    ldr r0, =0x1800
    bl lcd_cmd

    ldr r0, =0xc002
    bl lcd_dat

    ldr r0, =0x2000
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x4000
    bl lcd_cmd

    ldr r0, =0x1200
    bl lcd_dat

    ldr r0, =0x4800
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x5000
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x6000
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x6800
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x7800
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8000
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8800
    bl lcd_cmd

    ldr r0, =0x3800
    bl lcd_dat

    ldr r0, =0x9000
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x9800
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x3800
    bl lcd_cmd

    ldr r0, =0x800
    bl lcd_dat

    ldr r0, =0x8000
    bl lcd_cmd

    ldr r0, =0x8682
    bl lcd_dat

    ldr r0, =0x8800
    bl lcd_cmd

    ldr r0, =0x3e60
    bl lcd_dat

    ldr r0, =0x9000
    bl lcd_cmd

    ldr r0, =0xc080
    bl lcd_dat

    ldr r0, =0x9800
    bl lcd_cmd

    ldr r0, =0x603
    bl lcd_dat

    ldr r0, =0x4820
    bl lcd_cmd

    ldr r0, =0xf000
    bl lcd_dat

    ldr r0, =0x5820
    bl lcd_cmd

    ldr r0, =0x7000
    bl lcd_dat

    ldr r0, =0x20
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x820
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8020
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8820
    bl lcd_cmd

    ldr r0, =0x3d00
    bl lcd_dat

    ldr r0, =0x9020
    bl lcd_cmd

    ldr r0, =0x2000
    bl lcd_dat

    ldr r0, =0xa820
    bl lcd_cmd

    ldr r0, =0x2a00
    bl lcd_dat

    ldr r0, =0xb020
    bl lcd_cmd

    ldr r0, =0x2000
    bl lcd_dat

    ldr r0, =0xb820
    bl lcd_cmd

    ldr r0, =0x3b00
    bl lcd_dat

    ldr r0, =0xc020
    bl lcd_cmd

    ldr r0, =0x1000
    bl lcd_dat

    ldr r0, =0xc820
    bl lcd_cmd

    ldr r0, =0x3f00
    bl lcd_dat

    ldr r0, =0xe020
    bl lcd_cmd

    ldr r0, =0x1500
    bl lcd_dat

    ldr r0, =0xe820
    bl lcd_cmd

    ldr r0, =0x2000
    bl lcd_dat

    ldr r0, =0x8040
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8840
    bl lcd_cmd

    ldr r0, =0x78e0
    bl lcd_dat

    ldr r0, =0x9040
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x9840
    bl lcd_cmd

    ldr r0, =0xf920
    bl lcd_dat

    ldr r0, =0x60
    bl lcd_cmd

    ldr r0, =0x714
    bl lcd_dat

    ldr r0, =0x860
    bl lcd_cmd

    ldr r0, =0x800
    bl lcd_dat

    ldr r0, =0x5060
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x80
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x880
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x1080
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x1880
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x2080
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x2880
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8080
    bl lcd_cmd

    ldr r0, =0x8000
    bl lcd_dat

    ldr r0, =0x9080
    bl lcd_cmd

    ldr r0, =0x600
    bl lcd_dat

    ldr r0, =0x1800
    bl lcd_cmd

    ldr r0, =0x4020
    bl lcd_dat

    ldr r0, =0x3800
    bl lcd_cmd

    ldr r0, =0x9920
    bl lcd_dat

    ldr r0, =0x8040
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x8840
    bl lcd_cmd

    ldr r0, =0x78e0
    bl lcd_dat

    ldr r0, =0x9040
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x9840
    bl lcd_cmd

    ldr r0, =0xf920
    bl lcd_dat

    ldr r0, =0x20
    bl lcd_cmd

    ldr r0, =0x78e0
    bl lcd_dat

    ldr r0, =0x820
    bl lcd_cmd

    ldr r0, =0x0
    bl lcd_dat

    ldr r0, =0x1020
    bl lcd_cmd

    ldr r4, =320*80
    ldr r5, =0x1f
0:
    mov r0, r5
    bl lcd_dat
    subs r4, #1
    bne 0b
    
    ldr r4, =320*80
    ldr r5, =0x7e0
0:
    mov r0, r5
    bl lcd_dat
    subs r4, #1
    bne 0b
    
    ldr r4, =320*80
    ldr r5, =0xf800
0:
    mov r0, r5
    bl lcd_dat
    subs r4, #1
    bne 0b
    b .

delay:
    push {lr}
0:
    subs r0, #1
    bne 0b
    pop {pc}

lcd_rst:
    push {r4, r5, lr}
    ldr r4, =PIO_BASE + PE
    ldr r5, =0xffffffff

    bic r5, #LCD_RST
    str r5, [r4, #PIO_DATA]
    ldr r0, =10000
    bl delay

    orr r5, #LCD_RST
    str r5, [r4, #PIO_DATA]
    ldr r0, =10000
    bl delay
    pop {r4, r5, pc}

lcd_wr:
    push {r4, r5, lr}
    ldr r4, =PIO_BASE + PD

    and r2, r0, #0x00ff
    and r3, r0, #0xff00
    lsl r2, #1
    lsl r3, #2

    eor r5, r5
    orr r5, r1
    orr r5, r2
    orr r5, r3
    orr r5, #LCD_RD
    str r5, [r4, #PIO_DATA]

    orr r5, #LCD_WR
    str r5, [r4, #PIO_DATA]
    pop {r4, r5, pc}

lcd_dat:
    push {lr}
    mov r1, #LCD_RS
    bl lcd_wr
    pop {pc}

lcd_cmd:
    push {lr}
    mov r1, #0
    bl lcd_wr
    pop {pc}
    .end

感動的一刻


從觀察結果來看，R和B的資料是交換使用