[picodrive.git] / pico / cd / memory_arm.s

@*
@* Memory I/O handlers for Sega/Mega CD emulation
@* (C) notaz, 2007-2009
@*
@* This work is licensed under the terms of MAME license.
@* See COPYING file in the top-level directory.
@*

.equiv PCM_STEP_SHIFT, 11

.text
.align 2

.global PicoRead8_mcd_io
.global PicoRead16_mcd_io
.global PicoWrite8_mcd_io
.global PicoWrite16_mcd_io

.global PicoReadS68k8_pr
.global PicoReadS68k16_pr
.global PicoWriteS68k8_pr
.global PicoWriteS68k16_pr

.global PicoReadM68k8_cell0
.global PicoReadM68k8_cell1
.global PicoReadM68k16_cell0
.global PicoReadM68k16_cell1
.global PicoWriteM68k8_cell0
.global PicoWriteM68k8_cell1
.global PicoWriteM68k16_cell0
.global PicoWriteM68k16_cell1

.global PicoReadS68k8_dec0
.global PicoReadS68k8_dec1
.global PicoReadS68k16_dec0
.global PicoReadS68k16_dec1
.global PicoWriteS68k8_dec_m0b0
.global PicoWriteS68k8_dec_m1b0
.global PicoWriteS68k8_dec_m2b0
.global PicoWriteS68k8_dec_m0b1
.global PicoWriteS68k8_dec_m1b1
.global PicoWriteS68k8_dec_m2b1
.global PicoWriteS68k16_dec_m0b0
.global PicoWriteS68k16_dec_m1b0
.global PicoWriteS68k16_dec_m2b0
.global PicoWriteS68k16_dec_m0b1
.global PicoWriteS68k16_dec_m1b1
.global PicoWriteS68k16_dec_m2b1

@ externs, just for reference
.extern Pico
.extern cdc_host_r
.extern m68k_reg_write8
.extern s68k_reg_read16
.extern s68k_reg_write8
.extern s68k_reg_write16
.extern s68k_poll_detect
.extern pcd_pcm_write
.extern pcd_pcm_read
.extern PicoCpuCS68k
.extern PicoRead8_io
.extern PicoRead16_io
.extern PicoWrite8_io
.extern PicoWrite16_io
.extern m68k_comm_check


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

@ utilities

@ r0=addr[in,out], r1,r2=tmp
.macro cell_map
    ands    r1, r0, #0x01c000
    ldrne   pc, [pc, r1, lsr #12]
    beq     0f                          @ most common?
    .long   0f
    .long   0f
    .long   0f
    .long   0f
    .long   1f
    .long   1f
    .long   2f
    .long   3f
1: @ x16 cells
    and     r1, r0, #0x7e00             @ col
    and     r2, r0, #0x01fc             @ row
    orr     r2, r2, #0x0400
    orr     r1, r2, r1, ror #13
    b       9f
2: @ x8 cells
    and     r1, r0, #0x3f00             @ col
    and     r2, r0, #0x00fc             @ row
    orr     r2, r2, #0x0600
    orr     r1, r2, r1, ror #12
    b       9f
3: @ x4 cells
    and     r1, r0, #0x1f80             @ col
    and     r2, r0, #0x007c             @ row
    orr     r1, r2, r1, ror #11
    and     r2, r0,#0x1e000
    orr     r1, r1, r2, lsr #6
    b       9f
0: @ x32 cells
    and     r1, r0, #0xfc00             @ col
    and     r2, r0, #0x03fc             @ row
    orr     r1, r2, r1, ror #14
9:
    and     r0, r0, #3
    orr     r0, r0, r1, ror #26         @ rol 4+2
.endm


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


m_read_null:
    mov     r0, #0
    bx      lr


PicoReadM68k8_cell0:                    @ 0x220000 - 0x23ffff, cell arranged
    mov     r3, #0x0c0000
    b       0f

PicoReadM68k8_cell1:                    @ 0x220000 - 0x23ffff, cell arranged
    mov     r3, #0x0e0000
0:
    cell_map
    ldr     r1, =(Pico+0x22200)
    add     r0, r0, r3
    ldr     r1, [r1]
    eor     r0, r0, #1
    ldrb    r0, [r1, r0]
    bx      lr


PicoRead8_mcd_io:
    and     r1, r0, #0xff00
    cmp     r1, #0x2000	              @ a120xx?
    bne     PicoRead8_io

    ldr     r1, =(Pico+0x22200)
    and     r0, r0, #0x3f
    ldr     r1, [r1]                  @ Pico.mcd (used everywhere)
    cmp     r0, #0x0e
    ldrlt   pc, [pc, r0, lsl #2]
    b       m_m68k_read8_hi
    .long   m_m68k_read8_r00
    .long   m_m68k_read8_r01
    .long   m_m68k_read8_r02
    .long   m_m68k_read8_r03
    .long   m_m68k_read8_r04
    .long   m_read_null               @ unused bits
    .long   m_m68k_read8_r06
    .long   m_m68k_read8_r07
    .long   m_m68k_read8_r08
    .long   m_m68k_read8_r09
    .long   m_read_null               @ reserved
    .long   m_read_null
    .long   m_m68k_read8_r0c
    .long   m_m68k_read8_r0d
m_m68k_read8_r00:
    add     r1, r1, #0x110000
    ldr     r0, [r1, #0x30]
    and     r0, r0, #0x04000000       @ we need irq2 mask state
    mov     r0, r0, lsr #19
    bx      lr
m_m68k_read8_r01:
    add     r1, r1, #0x110000
    add     r1, r1, #0x002200
    ldrb    r0, [r1, #2]              @ Pico_mcd->m.busreq
    bx      lr
m_m68k_read8_r02:
    add     r1, r1, #0x110000
    ldrb    r0, [r1, #2]
    bx      lr
m_m68k_read8_r03:
    add     r1, r1, #0x110000
    push    {r1, lr}
    bl      m68k_comm_check
    pop     {r1, lr}
    ldrb    r0, [r1, #3]
    and     r0, r0, #0xc7
    bx      lr
m_m68k_read8_r04:
    add     r1, r1, #0x110000
    ldrb    r0, [r1, #4]
    bx      lr
m_m68k_read8_r06:
    ldrb    r0, [r1, #0x73]           @ IRQ vector
    bx      lr
m_m68k_read8_r07:
    ldrb    r0, [r1, #0x72]
    bx      lr
m_m68k_read8_r08:
    mov     r0, #0
    bl      cdc_host_r
    mov     r0, r0, lsr #8
    bx      lr
m_m68k_read8_r09:
    mov     r0, #0
    b       cdc_host_r
m_m68k_read8_r0c:
    add     r1, r1, #0x110000
    add     r1, r1, #0x002200
    ldr     r0, [r1, #0x14]           @ Pico_mcd->m.timer_stopwatch
    mov     r0, r0, lsr #24
    bx      lr
m_m68k_read8_r0d:
    add     r1, r1, #0x110000
    add     r1, r1, #0x002200
    ldr     r0, [r1, #0x14]
    mov     r0, r0, lsr #16
    bx      lr
m_m68k_read8_hi:
    cmp     r0, #0x30
    add     r1, r1, #0x110000
    movge   r0, #0
    bxge    lr
    add     r1, r0
    push    {r1, lr}
    bl      m68k_comm_check
    pop     {r1, lr}
    ldrb    r0, [r1]
    bx      lr


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


PicoReadM68k16_cell0:                   @ 0x220000 - 0x23ffff, cell arranged
    mov     r3, #0x0c0000
    b       0f

PicoReadM68k16_cell1:                   @ 0x220000 - 0x23ffff, cell arranged
    mov     r3, #0x0e0000
0:
    cell_map
    ldr     r1, =(Pico+0x22200)
    add     r0, r0, r3
    ldr     r1, [r1]
    bic     r0, r0, #1
    ldrh    r0, [r1, r0]
    bx      lr


PicoRead16_mcd_io:
    and     r1, r0, #0xff00
    cmp     r1, #0x2000	              @ a120xx
    bne     PicoRead16_io

m_m68k_read16_m68k_regs:
    ldr     r1, =(Pico+0x22200)
    and     r0, r0, #0x3e
    ldr     r1, [r1]                  @ Pico.mcd (used everywhere)
    cmp     r0, #0x0e
    ldrlt   pc, [pc, r0, lsl #1]
    b       m_m68k_read16_hi
    .long   m_m68k_read16_r00
    .long   m_m68k_read16_r02
    .long   m_m68k_read16_r04
    .long   m_m68k_read16_r06
    .long   m_m68k_read16_r08
    .long   m_read_null               @ reserved
    .long   m_m68k_read16_r0c
m_m68k_read16_r00:
    add     r1, r1, #0x110000
    ldr     r0, [r1, #0x30]
    add     r1, r1, #0x002200
    ldrb    r1, [r1, #2]              @ Pico_mcd->m.busreq
    and     r0, r0, #0x04000000       @ we need irq2 mask state
    orr     r0, r1, r0, lsr #11
    bx      lr
m_m68k_read16_r02:
    add     r1, r1, #0x110000
    push    {r1, lr}
    bl      m68k_comm_check
    pop     {r1, lr}
    ldrb    r2, [r1, #3]
    ldrb    r0, [r1, #2]
    and     r2, r2, #0xc7
    orr     r0, r2, r0, lsl #8
    bx      lr
m_m68k_read16_r04:
    add     r1, r1, #0x110000
    ldrb    r0, [r1, #4]
    mov     r0, r0, lsl #8
    bx      lr
m_m68k_read16_r06:
    ldrh    r0, [r1, #0x72]           @ IRQ vector
    bx      lr
m_m68k_read16_r08:
    mov     r0, #0
    b       cdc_host_r
m_m68k_read16_r0c:
    add     r1, r1, #0x110000
    add     r1, r1, #0x002200
    ldr     r0, [r1, #0x14]
    mov     r0, r0, lsr #16
    bx      lr
m_m68k_read16_hi:
    cmp     r0, #0x30
    add     r1, r1, #0x110000
    movge   r0, #0
    bxge    lr

    add     r1, r0, r1
    push    {r1, lr}
    bl      m68k_comm_check
    pop     {r0, lr}
    ldrh    r0, [r0]
    mov     r1, r0, lsr #8
    and     r0, r0, #0xff
    orr     r0, r1, r0, lsl #8
    bx      lr


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


PicoWriteM68k8_cell0:                   @ 0x220000 - 0x23ffff, cell arranged
    mov     r12,#0x0c0000
    b       0f

PicoWriteM68k8_cell1:                   @ 0x220000 - 0x23ffff, cell arranged
    mov     r12,#0x0e0000
0:
    mov     r3, r1
    cell_map
    ldr     r2, =(Pico+0x22200)
    add     r0, r0, r12
    ldr     r2, [r2]
    eor     r0, r0, #1
    strb    r3, [r2, r0]
    bx      lr


PicoWrite8_mcd_io:
    and     r2, r0, #0xff00
    cmp     r2, #0x2000                 @ a120xx?
    beq     m68k_reg_write8
    b       PicoWrite8_io


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


PicoWriteM68k16_cell0:                   @ 0x220000 - 0x23ffff, cell arranged
    mov     r12, #0x0c0000
    b       0f

PicoWriteM68k16_cell1:                   @ 0x220000 - 0x23ffff, cell arranged
    mov     r12, #0x0e0000
0:
    mov     r3, r1
    cell_map
    ldr     r1, =(Pico+0x22200)
    add     r0, r0, r12
    ldr     r1, [r1]
    bic     r0, r0, #1
    strh    r3, [r1, r0]
    bx      lr


PicoWrite16_mcd_io:
    and     r2, r0, #0xff00
    cmp     r2, #0x2000                 @ a120xx?
    bne     PicoWrite16_io

m_m68k_write16_regs:
    and     r0, r0, #0x3e
    cmp     r0, #0x0e
    beq     m_m68k_write16_regs_spec
    and     r3, r1, #0xff
    add     r2, r0, #1
    stmfd   sp!,{r2,r3,lr}
    mov     r1, r1, lsr #8
    bl      m68k_reg_write8
    ldmfd   sp!,{r0,r1,lr}
    b       m68k_reg_write8

m_m68k_write16_regs_spec:               @ special case
    mov     r1, r1, lsr #8
    b       m68k_reg_write8


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@                                   Sub 68k
@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


PicoReadS68k8_dec0:                     @ 0x080000 - 0x0bffff
    mov     r3, #0x080000               @ + ^ / 2
    b       0f

PicoReadS68k8_dec1:
    mov     r3, #0x0a0000               @ + ^ / 2
0:
    ldr     r2, =(Pico+0x22200)
    eor     r0, r0, #2
    ldr     r2, [r2]
    movs    r0, r0, lsr #1              @ +4-6 <<16
    add     r2, r2, r3                  @ map to our address
    ldrb    r0, [r2, r0]
    movcc   r0, r0, lsr #4
    andcs   r0, r0, #0xf
    bx      lr


PicoReadS68k8_pr:
    and     r2, r0, #0xfe00
    cmp     r2, #0x8000
    bne     m_s68k_read8_pcm

m_s68k_read8_regs:
    bic     r0, r0, #0xff0000
    bic     r0, r0, #0x008000
    sub     r2, r0, #0x0e
    cmp     r2, #(0x30-0x0e)
    blo     m_s68k_read8_comm
    stmfd   sp!,{r0,lr}
    bic     r0, r0, #1
    bl      s68k_reg_read16
    ldmfd   sp!,{r1,lr}
    tst     r1, #1
    moveq   r0, r0, lsr #8
    and     r0, r0, #0xff
    bx      lr

m_s68k_read8_comm:
    ldr     r1, =(Pico+0x22200)
    ldr     r1, [r1]
    add     r1, r1, #0x110000
    ldrb    r1, [r1, r0]
    bic     r0, r0, #1
    b       s68k_poll_detect


m_s68k_read8_pcm:
    tst     r0, #0x8000
    bne     m_read_null

    @ must not trash r3 and r12
    ldr     r1, =(Pico+0x22200)
    bic     r0, r0, #0xff0000
    ldr     r1, [r1]
    mov     r2, #0x110000
    orr     r2, r2, #0x002200
    cmp     r0, #0x2000
    bge     m_s68k_read8_pcm_ram
    cmp     r0, #0x20
    movge   r0, r0, lsr #1
    bge     pcd_pcm_read
    mov     r0, #0
    bx      lr

m_s68k_read8_pcm_ram:
    orr     r2, r2, #0x40
    ldr     r2, [r1, r2]
    add     r1, r1, #0x100000           @ pcm_ram
    and     r2, r2, #0x0f000000         @ bank
    add     r1, r1, r2, lsr #12
    bic     r0, r0, #0x00e000
    mov     r0, r0, lsr #1
    ldrb    r0, [r1, r0]
    bx      lr


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


PicoReadS68k16_dec0:                    @ 0x080000 - 0x0bffff
    mov     r3, #0x080000               @ + ^ / 2
    b       0f

PicoReadS68k16_dec1:
    mov     r3, #0x0a0000               @ + ^ / 2
0:
    ldr     r2, =(Pico+0x22200)
    eor     r0, r0, #2
    ldr     r2, [r2]
    mov     r0, r0, lsr #1              @ +4-6 <<16
    add     r2, r2, r3                  @ map to our address
    ldrb    r0, [r2, r0]
    orr     r0, r0, r0, lsl #4
    bic     r0, r0, #0xf0
    bx      lr


PicoReadS68k16_pr:
    and     r2, r0, #0xfe00
    cmp     r2, #0x8000
    @ pcm is on 8-bit bus, would this be same as byte access?
    bne     m_s68k_read8_pcm

m_s68k_read16_regs:
    bic     r0, r0, #0xff0000
    bic     r0, r0, #0x008000
    bic     r0, r0, #0x000001
    cmp     r0, #8
    bne     s68k_reg_read16
    mov     r0, #1
    b       cdc_host_r


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


.macro m_s68k_write8_2M_decode
    ldr     r2, =(Pico+0x22200)
    eor     r0, r0, #2
    ldr     r2, [r2]			@ Pico.rom
    movs    r0, r0, lsr #1              @ +4-6 <<16
    add     r2, r2, r3                  @ map to our address
.endm

PicoWriteS68k8_dec_m2b0:                @ overwrite
    ands    r1, r1, #0x0f
    bxeq    lr

PicoWriteS68k8_dec_m0b0:
    mov     r3, #0x080000
    b       0f

PicoWriteS68k8_dec_m2b1:                @ overwrite
    ands    r1, r1, #0x0f
    bxeq    lr

PicoWriteS68k8_dec_m0b1:
    mov     r3, #0x0a0000
0:
    m_s68k_write8_2M_decode
    ldrb    r0, [r2, r0]!
    and     r1, r1, #0x0f
    movcc   r1, r1, lsl #4
    andcc   r3, r0, #0x0f
    andcs   r3, r0, #0xf0
    orr     r3, r3, r1
    strneb  r3, [r2]
    bx      lr

PicoWriteS68k8_dec_m1b0:                @ underwrite
    mov     r3, #0x080000
    b       0f

PicoWriteS68k8_dec_m1b1:
    mov     r3, #0x0a0000
0:
    ands    r1, r1, #0x0f
    bxeq    lr
    m_s68k_write8_2M_decode
    ldrb    r0, [r2, r0]!
    movcc   r1, r1, lsl #4
    andcc   r3, r0, #0x0f
    andcs   r3, r0, #0xf0
    teq     r3, r0
    bxne    lr
    orr     r3, r3, r1
    strneb  r3, [r2]
    bx      lr


PicoWriteS68k8_pr:
    and     r2, r0, #0xfe00
    cmp     r2, #0x8000
    bne     m_s68k_write8_pcm

m_s68k_write8_regs:
    bic     r0, r0, #0xff0000
    bic     r0, r0, #0x008000
    tst     r0, #0x7e00
    movne   r0, #0
    bxne    lr
    sub     r2, r0, #0x59
    cmp     r2, #0x0f
    bhs     s68k_reg_write8
    bic     r0, r0, #1
    orr     r1, r1, r1, lsl #8
    b       s68k_reg_write16


m_s68k_write8_pcm:
    tst     r0, #0x8000
    bxne    lr
    bic     r0, r0, #0xff0000
    cmp     r0, #0x12
    movlt   r0, r0, lsr #1
    blt     pcd_pcm_write

    cmp     r0, #0x2000
    bxlt    lr

m_s68k_write8_pcm_ram:
    ldr     r3, =(Pico+0x22200)
    bic     r0, r0, #0x00e000
    ldr     r3, [r3]
    mov     r0, r0, lsr #1
    add     r2, r3, #0x110000
    add     r2, r2, #0x002200
    add     r2, r2, #0x000040
    ldr     r2, [r2]
    add     r3, r3, #0x100000           @ pcm_ram
    and     r2, r2, #0x0f000000         @ bank
    add     r3, r3, r2, lsr #12
    strb    r1, [r3, r0]
    bx      lr


@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


.macro m_s68k_write16_2M_decode
    ldr     r2, =(Pico+0x22200)
    eor     r0, r0, #2
    ldr     r2, [r2]
    mov     r0, r0, lsr #1              @ +4-6 <<16
    add     r2, r2, r3                  @ map to our address
.endm

PicoWriteS68k16_dec_m0b0:
    mov     r3, #0x080000
    b       0f

PicoWriteS68k16_dec_m0b1:
    mov     r3, #0x0a0000
0:
    m_s68k_write16_2M_decode
    bic     r1, r1, #0xf0
    orr     r1, r1, r1, lsr #4
    strb    r1, [r2, r0]
    bx      lr

PicoWriteS68k16_dec_m1b0:               @ underwrite
    mov     r3, #0x080000
    b       0f

PicoWriteS68k16_dec_m1b1:
    mov     r3, #0x0a0000
0:
    bics    r1, r1, #0xf000
    bicnes  r1, r1, #0x00f0
    bxeq    lr
    orr     r1, r1, r1, lsr #4
    m_s68k_write16_2M_decode
    ldrb    r0, [r2, r0]!
    and     r3, r1, #0x0f
    and     r1, r1, #0xf0
    tst     r0, #0x0f
    orreq   r0, r0, r3
    tst     r0, #0xf0
    orreq   r0, r0, r1
    strb    r0, [r2]
    bx      lr

PicoWriteS68k16_dec_m2b0:               @ overwrite
    mov     r3, #0x080000
    b       0f

PicoWriteS68k16_dec_m2b1:
    mov     r3, #0x0a0000
0:
    bics    r1, r1, #0xf000
    bicnes  r1, r1, #0x00f0
    bxeq    lr
    orr     r1, r1, r1, lsr #4
    m_s68k_write16_2M_decode
    ldrb    r0, [r2, r0]!
    ands    r3, r1, #0x0f
    andne   r0, r0, #0xf0
    orrne   r0, r0, r3
    ands    r1, r1, #0xf0
    andne   r0, r0, #0x0f
    orrne   r0, r0, r1
    strb    r0, [r2]
    bx      lr


PicoWriteS68k16_pr:
    and     r2, r0, #0xfe00
    cmp     r2, #0x8000
    bne     m_s68k_write8_pcm

m_s68k_write16_regs:
    bic     r0, r0, #0xff0000
    bic     r0, r0, #0x008000
    bic     r0, r0, #1
    tst     r0, #0x7e00
    movne   r0, #0
    bxne    lr
    cmp     r0, #0x0e
    bne     s68k_reg_write16

m_s68k_write16_regs_spec:               @ special case
    ldr     r2, =(Pico+0x22200)
    mov     r0, #0x110000
    ldr     r2, [r2]
    add     r0, r0, #0x00000f
    strb    r1, [r2, r0]                @ if (a == 0xe) s68k_regs[0xf] = d;
    bx      lr

.pool

@ vim:filetype=armasm
Commit	Line	Data
	1	@*
	2	@* Memory I/O handlers for Sega/Mega CD emulation
	3	@* (C) notaz, 2007-2009
	4	@*
	5	@* This work is licensed under the terms of MAME license.
	6	@* See COPYING file in the top-level directory.
	7	@*
	8
	9	.equiv PCM_STEP_SHIFT, 11
	10
	11	.text
	12	.align 2
	13
	14	.global PicoRead8_mcd_io
	15	.global PicoRead16_mcd_io
	16	.global PicoWrite8_mcd_io
	17	.global PicoWrite16_mcd_io
	18
	19	.global PicoReadS68k8_pr
	20	.global PicoReadS68k16_pr
	21	.global PicoWriteS68k8_pr
	22	.global PicoWriteS68k16_pr
	23
	24	.global PicoReadM68k8_cell0
	25	.global PicoReadM68k8_cell1
	26	.global PicoReadM68k16_cell0
	27	.global PicoReadM68k16_cell1
	28	.global PicoWriteM68k8_cell0
	29	.global PicoWriteM68k8_cell1
	30	.global PicoWriteM68k16_cell0
	31	.global PicoWriteM68k16_cell1
	32
	33	.global PicoReadS68k8_dec0
	34	.global PicoReadS68k8_dec1
	35	.global PicoReadS68k16_dec0
	36	.global PicoReadS68k16_dec1
	37	.global PicoWriteS68k8_dec_m0b0
	38	.global PicoWriteS68k8_dec_m1b0
	39	.global PicoWriteS68k8_dec_m2b0
	40	.global PicoWriteS68k8_dec_m0b1
	41	.global PicoWriteS68k8_dec_m1b1
	42	.global PicoWriteS68k8_dec_m2b1
	43	.global PicoWriteS68k16_dec_m0b0
	44	.global PicoWriteS68k16_dec_m1b0
	45	.global PicoWriteS68k16_dec_m2b0
	46	.global PicoWriteS68k16_dec_m0b1
	47	.global PicoWriteS68k16_dec_m1b1
	48	.global PicoWriteS68k16_dec_m2b1
	49
	50	@ externs, just for reference
	51	.extern Pico
	52	.extern cdc_host_r
	53	.extern m68k_reg_write8
	54	.extern s68k_reg_read16
	55	.extern s68k_reg_write8
	56	.extern s68k_reg_write16
	57	.extern s68k_poll_detect
	58	.extern pcd_pcm_write
	59	.extern pcd_pcm_read
	60	.extern PicoCpuCS68k
	61	.extern PicoRead8_io
	62	.extern PicoRead16_io
	63	.extern PicoWrite8_io
	64	.extern PicoWrite16_io
	65	.extern m68k_comm_check
	66
	67
	68	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	69
	70	@ utilities
	71
	72	@ r0=addr[in,out], r1,r2=tmp
	73	.macro cell_map
	74	ands r1, r0, #0x01c000
	75	ldrne pc, [pc, r1, lsr #12]
	76	beq 0f @ most common?
	77	.long 0f
	78	.long 0f
	79	.long 0f
	80	.long 0f
	81	.long 1f
	82	.long 1f
	83	.long 2f
	84	.long 3f
	85	1: @ x16 cells
	86	and r1, r0, #0x7e00 @ col
	87	and r2, r0, #0x01fc @ row
	88	orr r2, r2, #0x0400
	89	orr r1, r2, r1, ror #13
	90	b 9f
	91	2: @ x8 cells
	92	and r1, r0, #0x3f00 @ col
	93	and r2, r0, #0x00fc @ row
	94	orr r2, r2, #0x0600
	95	orr r1, r2, r1, ror #12
	96	b 9f
	97	3: @ x4 cells
	98	and r1, r0, #0x1f80 @ col
	99	and r2, r0, #0x007c @ row
	100	orr r1, r2, r1, ror #11
	101	and r2, r0,#0x1e000
	102	orr r1, r1, r2, lsr #6
	103	b 9f
	104	0: @ x32 cells
	105	and r1, r0, #0xfc00 @ col
	106	and r2, r0, #0x03fc @ row
	107	orr r1, r2, r1, ror #14
	108	9:
	109	and r0, r0, #3
	110	orr r0, r0, r1, ror #26 @ rol 4+2
	111	.endm
	112
	113
	114	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	115
	116
	117	m_read_null:
	118	mov r0, #0
	119	bx lr
	120
	121
	122	PicoReadM68k8_cell0: @ 0x220000 - 0x23ffff, cell arranged
	123	mov r3, #0x0c0000
	124	b 0f
	125
	126	PicoReadM68k8_cell1: @ 0x220000 - 0x23ffff, cell arranged
	127	mov r3, #0x0e0000
	128	0:
	129	cell_map
	130	ldr r1, =(Pico+0x22200)
	131	add r0, r0, r3
	132	ldr r1, [r1]
	133	eor r0, r0, #1
	134	ldrb r0, [r1, r0]
	135	bx lr
	136
	137
	138	PicoRead8_mcd_io:
	139	and r1, r0, #0xff00
	140	cmp r1, #0x2000 @ a120xx?
	141	bne PicoRead8_io
	142
	143	ldr r1, =(Pico+0x22200)
	144	and r0, r0, #0x3f
	145	ldr r1, [r1] @ Pico.mcd (used everywhere)
	146	cmp r0, #0x0e
	147	ldrlt pc, [pc, r0, lsl #2]
	148	b m_m68k_read8_hi
	149	.long m_m68k_read8_r00
	150	.long m_m68k_read8_r01
	151	.long m_m68k_read8_r02
	152	.long m_m68k_read8_r03
	153	.long m_m68k_read8_r04
	154	.long m_read_null @ unused bits
	155	.long m_m68k_read8_r06
	156	.long m_m68k_read8_r07
	157	.long m_m68k_read8_r08
	158	.long m_m68k_read8_r09
	159	.long m_read_null @ reserved
	160	.long m_read_null
	161	.long m_m68k_read8_r0c
	162	.long m_m68k_read8_r0d
	163	m_m68k_read8_r00:
	164	add r1, r1, #0x110000
	165	ldr r0, [r1, #0x30]
	166	and r0, r0, #0x04000000 @ we need irq2 mask state
	167	mov r0, r0, lsr #19
	168	bx lr
	169	m_m68k_read8_r01:
	170	add r1, r1, #0x110000
	171	add r1, r1, #0x002200
	172	ldrb r0, [r1, #2] @ Pico_mcd->m.busreq
	173	bx lr
	174	m_m68k_read8_r02:
	175	add r1, r1, #0x110000
	176	ldrb r0, [r1, #2]
	177	bx lr
	178	m_m68k_read8_r03:
	179	add r1, r1, #0x110000
	180	push {r1, lr}
	181	bl m68k_comm_check
	182	pop {r1, lr}
	183	ldrb r0, [r1, #3]
	184	and r0, r0, #0xc7
	185	bx lr
	186	m_m68k_read8_r04:
	187	add r1, r1, #0x110000
	188	ldrb r0, [r1, #4]
	189	bx lr
	190	m_m68k_read8_r06:
	191	ldrb r0, [r1, #0x73] @ IRQ vector
	192	bx lr
	193	m_m68k_read8_r07:
	194	ldrb r0, [r1, #0x72]
	195	bx lr
	196	m_m68k_read8_r08:
	197	mov r0, #0
	198	bl cdc_host_r
	199	mov r0, r0, lsr #8
	200	bx lr
	201	m_m68k_read8_r09:
	202	mov r0, #0
	203	b cdc_host_r
	204	m_m68k_read8_r0c:
	205	add r1, r1, #0x110000
	206	add r1, r1, #0x002200
	207	ldr r0, [r1, #0x14] @ Pico_mcd->m.timer_stopwatch
	208	mov r0, r0, lsr #24
	209	bx lr
	210	m_m68k_read8_r0d:
	211	add r1, r1, #0x110000
	212	add r1, r1, #0x002200
	213	ldr r0, [r1, #0x14]
	214	mov r0, r0, lsr #16
	215	bx lr
	216	m_m68k_read8_hi:
	217	cmp r0, #0x30
	218	add r1, r1, #0x110000
	219	movge r0, #0
	220	bxge lr
	221	add r1, r0
	222	push {r1, lr}
	223	bl m68k_comm_check
	224	pop {r1, lr}
	225	ldrb r0, [r1]
	226	bx lr
	227
	228
	229	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	230
	231
	232	PicoReadM68k16_cell0: @ 0x220000 - 0x23ffff, cell arranged
	233	mov r3, #0x0c0000
	234	b 0f
	235
	236	PicoReadM68k16_cell1: @ 0x220000 - 0x23ffff, cell arranged
	237	mov r3, #0x0e0000
	238	0:
	239	cell_map
	240	ldr r1, =(Pico+0x22200)
	241	add r0, r0, r3
	242	ldr r1, [r1]
	243	bic r0, r0, #1
	244	ldrh r0, [r1, r0]
	245	bx lr
	246
	247
	248	PicoRead16_mcd_io:
	249	and r1, r0, #0xff00
	250	cmp r1, #0x2000 @ a120xx
	251	bne PicoRead16_io
	252
	253	m_m68k_read16_m68k_regs:
	254	ldr r1, =(Pico+0x22200)
	255	and r0, r0, #0x3e
	256	ldr r1, [r1] @ Pico.mcd (used everywhere)
	257	cmp r0, #0x0e
	258	ldrlt pc, [pc, r0, lsl #1]
	259	b m_m68k_read16_hi
	260	.long m_m68k_read16_r00
	261	.long m_m68k_read16_r02
	262	.long m_m68k_read16_r04
	263	.long m_m68k_read16_r06
	264	.long m_m68k_read16_r08
	265	.long m_read_null @ reserved
	266	.long m_m68k_read16_r0c
	267	m_m68k_read16_r00:
	268	add r1, r1, #0x110000
	269	ldr r0, [r1, #0x30]
	270	add r1, r1, #0x002200
	271	ldrb r1, [r1, #2] @ Pico_mcd->m.busreq
	272	and r0, r0, #0x04000000 @ we need irq2 mask state
	273	orr r0, r1, r0, lsr #11
	274	bx lr
	275	m_m68k_read16_r02:
	276	add r1, r1, #0x110000
	277	push {r1, lr}
	278	bl m68k_comm_check
	279	pop {r1, lr}
	280	ldrb r2, [r1, #3]
	281	ldrb r0, [r1, #2]
	282	and r2, r2, #0xc7
	283	orr r0, r2, r0, lsl #8
	284	bx lr
	285	m_m68k_read16_r04:
	286	add r1, r1, #0x110000
	287	ldrb r0, [r1, #4]
	288	mov r0, r0, lsl #8
	289	bx lr
	290	m_m68k_read16_r06:
	291	ldrh r0, [r1, #0x72] @ IRQ vector
	292	bx lr
	293	m_m68k_read16_r08:
	294	mov r0, #0
	295	b cdc_host_r
	296	m_m68k_read16_r0c:
	297	add r1, r1, #0x110000
	298	add r1, r1, #0x002200
	299	ldr r0, [r1, #0x14]
	300	mov r0, r0, lsr #16
	301	bx lr
	302	m_m68k_read16_hi:
	303	cmp r0, #0x30
	304	add r1, r1, #0x110000
	305	movge r0, #0
	306	bxge lr
	307
	308	add r1, r0, r1
	309	push {r1, lr}
	310	bl m68k_comm_check
	311	pop {r0, lr}
	312	ldrh r0, [r0]
	313	mov r1, r0, lsr #8
	314	and r0, r0, #0xff
	315	orr r0, r1, r0, lsl #8
	316	bx lr
	317
	318
	319	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	320
	321
	322	PicoWriteM68k8_cell0: @ 0x220000 - 0x23ffff, cell arranged
	323	mov r12,#0x0c0000
	324	b 0f
	325
	326	PicoWriteM68k8_cell1: @ 0x220000 - 0x23ffff, cell arranged
	327	mov r12,#0x0e0000
	328	0:
	329	mov r3, r1
	330	cell_map
	331	ldr r2, =(Pico+0x22200)
	332	add r0, r0, r12
	333	ldr r2, [r2]
	334	eor r0, r0, #1
	335	strb r3, [r2, r0]
	336	bx lr
	337
	338
	339	PicoWrite8_mcd_io:
	340	and r2, r0, #0xff00
	341	cmp r2, #0x2000 @ a120xx?
	342	beq m68k_reg_write8
	343	b PicoWrite8_io
	344
	345
	346	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	347
	348
	349	PicoWriteM68k16_cell0: @ 0x220000 - 0x23ffff, cell arranged
	350	mov r12, #0x0c0000
	351	b 0f
	352
	353	PicoWriteM68k16_cell1: @ 0x220000 - 0x23ffff, cell arranged
	354	mov r12, #0x0e0000
	355	0:
	356	mov r3, r1
	357	cell_map
	358	ldr r1, =(Pico+0x22200)
	359	add r0, r0, r12
	360	ldr r1, [r1]
	361	bic r0, r0, #1
	362	strh r3, [r1, r0]
	363	bx lr
	364
	365
	366	PicoWrite16_mcd_io:
	367	and r2, r0, #0xff00
	368	cmp r2, #0x2000 @ a120xx?
	369	bne PicoWrite16_io
	370
	371	m_m68k_write16_regs:
	372	and r0, r0, #0x3e
	373	cmp r0, #0x0e
	374	beq m_m68k_write16_regs_spec
	375	and r3, r1, #0xff
	376	add r2, r0, #1
	377	stmfd sp!,{r2,r3,lr}
	378	mov r1, r1, lsr #8
	379	bl m68k_reg_write8
	380	ldmfd sp!,{r0,r1,lr}
	381	b m68k_reg_write8
	382
	383	m_m68k_write16_regs_spec: @ special case
	384	mov r1, r1, lsr #8
	385	b m68k_reg_write8
	386
	387
	388	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	389	@ Sub 68k
	390	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	391
	392
	393	PicoReadS68k8_dec0: @ 0x080000 - 0x0bffff
	394	mov r3, #0x080000 @ + ^ / 2
	395	b 0f
	396
	397	PicoReadS68k8_dec1:
	398	mov r3, #0x0a0000 @ + ^ / 2
	399	0:
	400	ldr r2, =(Pico+0x22200)
	401	eor r0, r0, #2
	402	ldr r2, [r2]
	403	movs r0, r0, lsr #1 @ +4-6 <<16
	404	add r2, r2, r3 @ map to our address
	405	ldrb r0, [r2, r0]
	406	movcc r0, r0, lsr #4
	407	andcs r0, r0, #0xf
	408	bx lr
	409
	410
	411	PicoReadS68k8_pr:
	412	and r2, r0, #0xfe00
	413	cmp r2, #0x8000
	414	bne m_s68k_read8_pcm
	415
	416	m_s68k_read8_regs:
	417	bic r0, r0, #0xff0000
	418	bic r0, r0, #0x008000
	419	sub r2, r0, #0x0e
	420	cmp r2, #(0x30-0x0e)
	421	blo m_s68k_read8_comm
	422	stmfd sp!,{r0,lr}
	423	bic r0, r0, #1
	424	bl s68k_reg_read16
	425	ldmfd sp!,{r1,lr}
	426	tst r1, #1
	427	moveq r0, r0, lsr #8
	428	and r0, r0, #0xff
	429	bx lr
	430
	431	m_s68k_read8_comm:
	432	ldr r1, =(Pico+0x22200)
	433	ldr r1, [r1]
	434	add r1, r1, #0x110000
	435	ldrb r1, [r1, r0]
	436	bic r0, r0, #1
	437	b s68k_poll_detect
	438
	439
	440	m_s68k_read8_pcm:
	441	tst r0, #0x8000
	442	bne m_read_null
	443
	444	@ must not trash r3 and r12
	445	ldr r1, =(Pico+0x22200)
	446	bic r0, r0, #0xff0000
	447	ldr r1, [r1]
	448	mov r2, #0x110000
	449	orr r2, r2, #0x002200
	450	cmp r0, #0x2000
	451	bge m_s68k_read8_pcm_ram
	452	cmp r0, #0x20
	453	movge r0, r0, lsr #1
	454	bge pcd_pcm_read
	455	mov r0, #0
	456	bx lr
	457
	458	m_s68k_read8_pcm_ram:
	459	orr r2, r2, #0x40
	460	ldr r2, [r1, r2]
	461	add r1, r1, #0x100000 @ pcm_ram
	462	and r2, r2, #0x0f000000 @ bank
	463	add r1, r1, r2, lsr #12
	464	bic r0, r0, #0x00e000
	465	mov r0, r0, lsr #1
	466	ldrb r0, [r1, r0]
	467	bx lr
	468
	469
	470	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	471
	472
	473	PicoReadS68k16_dec0: @ 0x080000 - 0x0bffff
	474	mov r3, #0x080000 @ + ^ / 2
	475	b 0f
	476
	477	PicoReadS68k16_dec1:
	478	mov r3, #0x0a0000 @ + ^ / 2
	479	0:
	480	ldr r2, =(Pico+0x22200)
	481	eor r0, r0, #2
	482	ldr r2, [r2]
	483	mov r0, r0, lsr #1 @ +4-6 <<16
	484	add r2, r2, r3 @ map to our address
	485	ldrb r0, [r2, r0]
	486	orr r0, r0, r0, lsl #4
	487	bic r0, r0, #0xf0
	488	bx lr
	489
	490
	491	PicoReadS68k16_pr:
	492	and r2, r0, #0xfe00
	493	cmp r2, #0x8000
	494	@ pcm is on 8-bit bus, would this be same as byte access?
	495	bne m_s68k_read8_pcm
	496
	497	m_s68k_read16_regs:
	498	bic r0, r0, #0xff0000
	499	bic r0, r0, #0x008000
	500	bic r0, r0, #0x000001
	501	cmp r0, #8
	502	bne s68k_reg_read16
	503	mov r0, #1
	504	b cdc_host_r
	505
	506
	507	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	508
	509
	510	.macro m_s68k_write8_2M_decode
	511	ldr r2, =(Pico+0x22200)
	512	eor r0, r0, #2
	513	ldr r2, [r2] @ Pico.rom
	514	movs r0, r0, lsr #1 @ +4-6 <<16
	515	add r2, r2, r3 @ map to our address
	516	.endm
	517
	518	PicoWriteS68k8_dec_m2b0: @ overwrite
	519	ands r1, r1, #0x0f
	520	bxeq lr
	521
	522	PicoWriteS68k8_dec_m0b0:
	523	mov r3, #0x080000
	524	b 0f
	525
	526	PicoWriteS68k8_dec_m2b1: @ overwrite
	527	ands r1, r1, #0x0f
	528	bxeq lr
	529
	530	PicoWriteS68k8_dec_m0b1:
	531	mov r3, #0x0a0000
	532	0:
	533	m_s68k_write8_2M_decode
	534	ldrb r0, [r2, r0]!
	535	and r1, r1, #0x0f
	536	movcc r1, r1, lsl #4
	537	andcc r3, r0, #0x0f
	538	andcs r3, r0, #0xf0
	539	orr r3, r3, r1
	540	strneb r3, [r2]
	541	bx lr
	542
	543	PicoWriteS68k8_dec_m1b0: @ underwrite
	544	mov r3, #0x080000
	545	b 0f
	546
	547	PicoWriteS68k8_dec_m1b1:
	548	mov r3, #0x0a0000
	549	0:
	550	ands r1, r1, #0x0f
	551	bxeq lr
	552	m_s68k_write8_2M_decode
	553	ldrb r0, [r2, r0]!
	554	movcc r1, r1, lsl #4
	555	andcc r3, r0, #0x0f
	556	andcs r3, r0, #0xf0
	557	teq r3, r0
	558	bxne lr
	559	orr r3, r3, r1
	560	strneb r3, [r2]
	561	bx lr
	562
	563
	564	PicoWriteS68k8_pr:
	565	and r2, r0, #0xfe00
	566	cmp r2, #0x8000
	567	bne m_s68k_write8_pcm
	568
	569	m_s68k_write8_regs:
	570	bic r0, r0, #0xff0000
	571	bic r0, r0, #0x008000
	572	tst r0, #0x7e00
	573	movne r0, #0
	574	bxne lr
	575	sub r2, r0, #0x59
	576	cmp r2, #0x0f
	577	bhs s68k_reg_write8
	578	bic r0, r0, #1
	579	orr r1, r1, r1, lsl #8
	580	b s68k_reg_write16
	581
	582
	583	m_s68k_write8_pcm:
	584	tst r0, #0x8000
	585	bxne lr
	586	bic r0, r0, #0xff0000
	587	cmp r0, #0x12
	588	movlt r0, r0, lsr #1
	589	blt pcd_pcm_write
	590
	591	cmp r0, #0x2000
	592	bxlt lr
	593
	594	m_s68k_write8_pcm_ram:
	595	ldr r3, =(Pico+0x22200)
	596	bic r0, r0, #0x00e000
	597	ldr r3, [r3]
	598	mov r0, r0, lsr #1
	599	add r2, r3, #0x110000
	600	add r2, r2, #0x002200
	601	add r2, r2, #0x000040
	602	ldr r2, [r2]
	603	add r3, r3, #0x100000 @ pcm_ram
	604	and r2, r2, #0x0f000000 @ bank
	605	add r3, r3, r2, lsr #12
	606	strb r1, [r3, r0]
	607	bx lr
	608
	609
	610	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	611
	612
	613	.macro m_s68k_write16_2M_decode
	614	ldr r2, =(Pico+0x22200)
	615	eor r0, r0, #2
	616	ldr r2, [r2]
	617	mov r0, r0, lsr #1 @ +4-6 <<16
	618	add r2, r2, r3 @ map to our address
	619	.endm
	620
	621	PicoWriteS68k16_dec_m0b0:
	622	mov r3, #0x080000
	623	b 0f
	624
	625	PicoWriteS68k16_dec_m0b1:
	626	mov r3, #0x0a0000
	627	0:
	628	m_s68k_write16_2M_decode
	629	bic r1, r1, #0xf0
	630	orr r1, r1, r1, lsr #4
	631	strb r1, [r2, r0]
	632	bx lr
	633
	634	PicoWriteS68k16_dec_m1b0: @ underwrite
	635	mov r3, #0x080000
	636	b 0f
	637
	638	PicoWriteS68k16_dec_m1b1:
	639	mov r3, #0x0a0000
	640	0:
	641	bics r1, r1, #0xf000
	642	bicnes r1, r1, #0x00f0
	643	bxeq lr
	644	orr r1, r1, r1, lsr #4
	645	m_s68k_write16_2M_decode
	646	ldrb r0, [r2, r0]!
	647	and r3, r1, #0x0f
	648	and r1, r1, #0xf0
	649	tst r0, #0x0f
	650	orreq r0, r0, r3
	651	tst r0, #0xf0
	652	orreq r0, r0, r1
	653	strb r0, [r2]
	654	bx lr
	655
	656	PicoWriteS68k16_dec_m2b0: @ overwrite
	657	mov r3, #0x080000
	658	b 0f
	659
	660	PicoWriteS68k16_dec_m2b1:
	661	mov r3, #0x0a0000
	662	0:
	663	bics r1, r1, #0xf000
	664	bicnes r1, r1, #0x00f0
	665	bxeq lr
	666	orr r1, r1, r1, lsr #4
	667	m_s68k_write16_2M_decode
	668	ldrb r0, [r2, r0]!
	669	ands r3, r1, #0x0f
	670	andne r0, r0, #0xf0
	671	orrne r0, r0, r3
	672	ands r1, r1, #0xf0
	673	andne r0, r0, #0x0f
	674	orrne r0, r0, r1
	675	strb r0, [r2]
	676	bx lr
	677
	678
	679	PicoWriteS68k16_pr:
	680	and r2, r0, #0xfe00
	681	cmp r2, #0x8000
	682	bne m_s68k_write8_pcm
	683
	684	m_s68k_write16_regs:
	685	bic r0, r0, #0xff0000
	686	bic r0, r0, #0x008000
	687	bic r0, r0, #1
	688	tst r0, #0x7e00
	689	movne r0, #0
	690	bxne lr
	691	cmp r0, #0x0e
	692	bne s68k_reg_write16
	693
	694	m_s68k_write16_regs_spec: @ special case
	695	ldr r2, =(Pico+0x22200)
	696	mov r0, #0x110000
	697	ldr r2, [r2]
	698	add r0, r0, #0x00000f
	699	strb r1, [r2, r0] @ if (a == 0xe) s68k_regs[0xf] = d;
	700	bx lr
	701
	702	.pool
	703
	704	@ vim:filetype=armasm