[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.
@*

#include "../pico_int_o32.h"

.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
    add     r0, r0, r3
    ldr     r1, [r1, #OFS_Pico_rom]   @ Pico.mcd (used everywhere)
    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
    and     r0, r0, #0x3f
    ldr     r1, [r1, #OFS_Pico_rom]   @ Pico.mcd
    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
    add     r0, r0, r3
    ldr     r1, [r1, #OFS_Pico_rom]   @ Pico.mcd
    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
    and     r0, r0, #0x3e
    ldr     r1, [r1, #OFS_Pico_rom]   @ Pico.mcd
    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
    add     r0, r0, r12
    ldr     r2, [r2, #OFS_Pico_rom]     @ Pico.mcd
    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
    add     r0, r0, r12
    ldr     r1, [r1, #OFS_Pico_rom]     @ Pico.mcd
    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
    eor     r0, r0, #2
    ldr     r2, [r2, #OFS_Pico_rom]     @ Pico.mcd
    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
    ldr     r1, [r1, #OFS_Pico_rom]     @ Pico.mcd
    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
    bic     r0, r0, #0xff0000
    ldr     r1, [r1, #OFS_Pico_rom]     @ Pico.mcd
    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
    eor     r0, r0, #2
    ldr     r2, [r2, #OFS_Pico_rom]     @ Pico.mcd
    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
    eor     r0, r0, #2
    ldr     r2, [r2, #OFS_Pico_rom]     @ Pico.mcd
    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
    bic     r0, r0, #0x00e000
    ldr     r3, [r3, #OFS_Pico_rom]     @ Pico.mcd
    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
    eor     r0, r0, #2
    ldr     r2, [r2, #OFS_Pico_rom]     @ Pico.mcd
    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
    mov     r0, #0x110000
    ldr     r2, [r2, #OFS_Pico_rom]     @ Pico.mcd
    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	#include "../pico_int_o32.h"
	10
	11	.equiv PCM_STEP_SHIFT, 11
	12
	13	.text
	14	.align 2
	15
	16	.global PicoRead8_mcd_io
	17	.global PicoRead16_mcd_io
	18	.global PicoWrite8_mcd_io
	19	.global PicoWrite16_mcd_io
	20
	21	.global PicoReadS68k8_pr
	22	.global PicoReadS68k16_pr
	23	.global PicoWriteS68k8_pr
	24	.global PicoWriteS68k16_pr
	25
	26	.global PicoReadM68k8_cell0
	27	.global PicoReadM68k8_cell1
	28	.global PicoReadM68k16_cell0
	29	.global PicoReadM68k16_cell1
	30	.global PicoWriteM68k8_cell0
	31	.global PicoWriteM68k8_cell1
	32	.global PicoWriteM68k16_cell0
	33	.global PicoWriteM68k16_cell1
	34
	35	.global PicoReadS68k8_dec0
	36	.global PicoReadS68k8_dec1
	37	.global PicoReadS68k16_dec0
	38	.global PicoReadS68k16_dec1
	39	.global PicoWriteS68k8_dec_m0b0
	40	.global PicoWriteS68k8_dec_m1b0
	41	.global PicoWriteS68k8_dec_m2b0
	42	.global PicoWriteS68k8_dec_m0b1
	43	.global PicoWriteS68k8_dec_m1b1
	44	.global PicoWriteS68k8_dec_m2b1
	45	.global PicoWriteS68k16_dec_m0b0
	46	.global PicoWriteS68k16_dec_m1b0
	47	.global PicoWriteS68k16_dec_m2b0
	48	.global PicoWriteS68k16_dec_m0b1
	49	.global PicoWriteS68k16_dec_m1b1
	50	.global PicoWriteS68k16_dec_m2b1
	51
	52	@ externs, just for reference
	53	.extern Pico
	54	.extern cdc_host_r
	55	.extern m68k_reg_write8
	56	.extern s68k_reg_read16
	57	.extern s68k_reg_write8
	58	.extern s68k_reg_write16
	59	.extern s68k_poll_detect
	60	.extern pcd_pcm_write
	61	.extern pcd_pcm_read
	62	.extern PicoCpuCS68k
	63	.extern PicoRead8_io
	64	.extern PicoRead16_io
	65	.extern PicoWrite8_io
	66	.extern PicoWrite16_io
	67	.extern m68k_comm_check
	68
	69
	70	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	71
	72	@ utilities
	73
	74	@ r0=addr[in,out], r1,r2=tmp
	75	.macro cell_map
	76	ands r1, r0, #0x01c000
	77	ldrne pc, [pc, r1, lsr #12]
	78	beq 0f @ most common?
	79	.long 0f
	80	.long 0f
	81	.long 0f
	82	.long 0f
	83	.long 1f
	84	.long 1f
	85	.long 2f
	86	.long 3f
	87	1: @ x16 cells
	88	and r1, r0, #0x7e00 @ col
	89	and r2, r0, #0x01fc @ row
	90	orr r2, r2, #0x0400
	91	orr r1, r2, r1, ror #13
	92	b 9f
	93	2: @ x8 cells
	94	and r1, r0, #0x3f00 @ col
	95	and r2, r0, #0x00fc @ row
	96	orr r2, r2, #0x0600
	97	orr r1, r2, r1, ror #12
	98	b 9f
	99	3: @ x4 cells
	100	and r1, r0, #0x1f80 @ col
	101	and r2, r0, #0x007c @ row
	102	orr r1, r2, r1, ror #11
	103	and r2, r0,#0x1e000
	104	orr r1, r1, r2, lsr #6
	105	b 9f
	106	0: @ x32 cells
	107	and r1, r0, #0xfc00 @ col
	108	and r2, r0, #0x03fc @ row
	109	orr r1, r2, r1, ror #14
	110	9:
	111	and r0, r0, #3
	112	orr r0, r0, r1, ror #26 @ rol 4+2
	113	.endm
	114
	115
	116	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	117
	118
	119	m_read_null:
	120	mov r0, #0
	121	bx lr
	122
	123
	124	PicoReadM68k8_cell0: @ 0x220000 - 0x23ffff, cell arranged
	125	mov r3, #0x0c0000
	126	b 0f
	127
	128	PicoReadM68k8_cell1: @ 0x220000 - 0x23ffff, cell arranged
	129	mov r3, #0x0e0000
	130	0:
	131	cell_map
	132	ldr r1, =Pico
	133	add r0, r0, r3
	134	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd (used everywhere)
	135	eor r0, r0, #1
	136	ldrb r0, [r1, r0]
	137	bx lr
	138
	139
	140	PicoRead8_mcd_io:
	141	and r1, r0, #0xff00
	142	cmp r1, #0x2000 @ a120xx?
	143	bne PicoRead8_io
	144
	145	ldr r1, =Pico
	146	and r0, r0, #0x3f
	147	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd
	148	cmp r0, #0x0e
	149	ldrlt pc, [pc, r0, lsl #2]
	150	b m_m68k_read8_hi
	151	.long m_m68k_read8_r00
	152	.long m_m68k_read8_r01
	153	.long m_m68k_read8_r02
	154	.long m_m68k_read8_r03
	155	.long m_m68k_read8_r04
	156	.long m_read_null @ unused bits
	157	.long m_m68k_read8_r06
	158	.long m_m68k_read8_r07
	159	.long m_m68k_read8_r08
	160	.long m_m68k_read8_r09
	161	.long m_read_null @ reserved
	162	.long m_read_null
	163	.long m_m68k_read8_r0c
	164	.long m_m68k_read8_r0d
	165	m_m68k_read8_r00:
	166	add r1, r1, #0x110000
	167	ldr r0, [r1, #0x30]
	168	and r0, r0, #0x04000000 @ we need irq2 mask state
	169	mov r0, r0, lsr #19
	170	bx lr
	171	m_m68k_read8_r01:
	172	add r1, r1, #0x110000
	173	add r1, r1, #0x002200
	174	ldrb r0, [r1, #2] @ Pico_mcd->m.busreq
	175	bx lr
	176	m_m68k_read8_r02:
	177	add r1, r1, #0x110000
	178	ldrb r0, [r1, #2]
	179	bx lr
	180	m_m68k_read8_r03:
	181	add r1, r1, #0x110000
	182	push {r1, lr}
	183	bl m68k_comm_check
	184	pop {r1, lr}
	185	ldrb r0, [r1, #3]
	186	and r0, r0, #0xc7
	187	bx lr
	188	m_m68k_read8_r04:
	189	add r1, r1, #0x110000
	190	ldrb r0, [r1, #4]
	191	bx lr
	192	m_m68k_read8_r06:
	193	ldrb r0, [r1, #0x73] @ IRQ vector
	194	bx lr
	195	m_m68k_read8_r07:
	196	ldrb r0, [r1, #0x72]
	197	bx lr
	198	m_m68k_read8_r08:
	199	mov r0, #0
	200	bl cdc_host_r
	201	mov r0, r0, lsr #8
	202	bx lr
	203	m_m68k_read8_r09:
	204	mov r0, #0
	205	b cdc_host_r
	206	m_m68k_read8_r0c:
	207	add r1, r1, #0x110000
	208	add r1, r1, #0x002200
	209	ldr r0, [r1, #0x14] @ Pico_mcd->m.timer_stopwatch
	210	mov r0, r0, lsr #24
	211	bx lr
	212	m_m68k_read8_r0d:
	213	add r1, r1, #0x110000
	214	add r1, r1, #0x002200
	215	ldr r0, [r1, #0x14]
	216	mov r0, r0, lsr #16
	217	bx lr
	218	m_m68k_read8_hi:
	219	cmp r0, #0x30
	220	add r1, r1, #0x110000
	221	movge r0, #0
	222	bxge lr
	223	add r1, r0
	224	push {r1, lr}
	225	bl m68k_comm_check
	226	pop {r1, lr}
	227	ldrb r0, [r1]
	228	bx lr
	229
	230
	231	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	232
	233
	234	PicoReadM68k16_cell0: @ 0x220000 - 0x23ffff, cell arranged
	235	mov r3, #0x0c0000
	236	b 0f
	237
	238	PicoReadM68k16_cell1: @ 0x220000 - 0x23ffff, cell arranged
	239	mov r3, #0x0e0000
	240	0:
	241	cell_map
	242	ldr r1, =Pico
	243	add r0, r0, r3
	244	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd
	245	bic r0, r0, #1
	246	ldrh r0, [r1, r0]
	247	bx lr
	248
	249
	250	PicoRead16_mcd_io:
	251	and r1, r0, #0xff00
	252	cmp r1, #0x2000 @ a120xx
	253	bne PicoRead16_io
	254
	255	m_m68k_read16_m68k_regs:
	256	ldr r1, =Pico
	257	and r0, r0, #0x3e
	258	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd
	259	cmp r0, #0x0e
	260	ldrlt pc, [pc, r0, lsl #1]
	261	b m_m68k_read16_hi
	262	.long m_m68k_read16_r00
	263	.long m_m68k_read16_r02
	264	.long m_m68k_read16_r04
	265	.long m_m68k_read16_r06
	266	.long m_m68k_read16_r08
	267	.long m_read_null @ reserved
	268	.long m_m68k_read16_r0c
	269	m_m68k_read16_r00:
	270	add r1, r1, #0x110000
	271	ldr r0, [r1, #0x30]
	272	add r1, r1, #0x002200
	273	ldrb r1, [r1, #2] @ Pico_mcd->m.busreq
	274	and r0, r0, #0x04000000 @ we need irq2 mask state
	275	orr r0, r1, r0, lsr #11
	276	bx lr
	277	m_m68k_read16_r02:
	278	add r1, r1, #0x110000
	279	push {r1, lr}
	280	bl m68k_comm_check
	281	pop {r1, lr}
	282	ldrb r2, [r1, #3]
	283	ldrb r0, [r1, #2]
	284	and r2, r2, #0xc7
	285	orr r0, r2, r0, lsl #8
	286	bx lr
	287	m_m68k_read16_r04:
	288	add r1, r1, #0x110000
	289	ldrb r0, [r1, #4]
	290	mov r0, r0, lsl #8
	291	bx lr
	292	m_m68k_read16_r06:
	293	ldrh r0, [r1, #0x72] @ IRQ vector
	294	bx lr
	295	m_m68k_read16_r08:
	296	mov r0, #0
	297	b cdc_host_r
	298	m_m68k_read16_r0c:
	299	add r1, r1, #0x110000
	300	add r1, r1, #0x002200
	301	ldr r0, [r1, #0x14]
	302	mov r0, r0, lsr #16
	303	bx lr
	304	m_m68k_read16_hi:
	305	cmp r0, #0x30
	306	add r1, r1, #0x110000
	307	movge r0, #0
	308	bxge lr
	309
	310	add r1, r0, r1
	311	push {r1, lr}
	312	bl m68k_comm_check
	313	pop {r0, lr}
	314	ldrh r0, [r0]
	315	mov r1, r0, lsr #8
	316	and r0, r0, #0xff
	317	orr r0, r1, r0, lsl #8
	318	bx lr
	319
	320
	321	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	322
	323
	324	PicoWriteM68k8_cell0: @ 0x220000 - 0x23ffff, cell arranged
	325	mov r12,#0x0c0000
	326	b 0f
	327
	328	PicoWriteM68k8_cell1: @ 0x220000 - 0x23ffff, cell arranged
	329	mov r12,#0x0e0000
	330	0:
	331	mov r3, r1
	332	cell_map
	333	ldr r2, =Pico
	334	add r0, r0, r12
	335	ldr r2, [r2, #OFS_Pico_rom] @ Pico.mcd
	336	ldr r2, [r2]
	337	eor r0, r0, #1
	338	strb r3, [r2, r0]
	339	bx lr
	340
	341
	342	PicoWrite8_mcd_io:
	343	and r2, r0, #0xff00
	344	cmp r2, #0x2000 @ a120xx?
	345	beq m68k_reg_write8
	346	b PicoWrite8_io
	347
	348
	349	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	350
	351
	352	PicoWriteM68k16_cell0: @ 0x220000 - 0x23ffff, cell arranged
	353	mov r12, #0x0c0000
	354	b 0f
	355
	356	PicoWriteM68k16_cell1: @ 0x220000 - 0x23ffff, cell arranged
	357	mov r12, #0x0e0000
	358	0:
	359	mov r3, r1
	360	cell_map
	361	ldr r1, =Pico
	362	add r0, r0, r12
	363	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd
	364	bic r0, r0, #1
	365	strh r3, [r1, r0]
	366	bx lr
	367
	368
	369	PicoWrite16_mcd_io:
	370	and r2, r0, #0xff00
	371	cmp r2, #0x2000 @ a120xx?
	372	bne PicoWrite16_io
	373
	374	m_m68k_write16_regs:
	375	and r0, r0, #0x3e
	376	cmp r0, #0x0e
	377	beq m_m68k_write16_regs_spec
	378	and r3, r1, #0xff
	379	add r2, r0, #1
	380	stmfd sp!,{r2,r3,lr}
	381	mov r1, r1, lsr #8
	382	bl m68k_reg_write8
	383	ldmfd sp!,{r0,r1,lr}
	384	b m68k_reg_write8
	385
	386	m_m68k_write16_regs_spec: @ special case
	387	mov r1, r1, lsr #8
	388	b m68k_reg_write8
	389
	390
	391	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	392	@ Sub 68k
	393	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	394
	395
	396	PicoReadS68k8_dec0: @ 0x080000 - 0x0bffff
	397	mov r3, #0x080000 @ + ^ / 2
	398	b 0f
	399
	400	PicoReadS68k8_dec1:
	401	mov r3, #0x0a0000 @ + ^ / 2
	402	0:
	403	ldr r2, =Pico
	404	eor r0, r0, #2
	405	ldr r2, [r2, #OFS_Pico_rom] @ Pico.mcd
	406	movs r0, r0, lsr #1 @ +4-6 <<16
	407	add r2, r2, r3 @ map to our address
	408	ldrb r0, [r2, r0]
	409	movcc r0, r0, lsr #4
	410	andcs r0, r0, #0xf
	411	bx lr
	412
	413
	414	PicoReadS68k8_pr:
	415	and r2, r0, #0xfe00
	416	cmp r2, #0x8000
	417	bne m_s68k_read8_pcm
	418
	419	m_s68k_read8_regs:
	420	bic r0, r0, #0xff0000
	421	bic r0, r0, #0x008000
	422	sub r2, r0, #0x0e
	423	cmp r2, #(0x30-0x0e)
	424	blo m_s68k_read8_comm
	425	stmfd sp!,{r0,lr}
	426	bic r0, r0, #1
	427	bl s68k_reg_read16
	428	ldmfd sp!,{r1,lr}
	429	tst r1, #1
	430	moveq r0, r0, lsr #8
	431	and r0, r0, #0xff
	432	bx lr
	433
	434	m_s68k_read8_comm:
	435	ldr r1, =Pico
	436	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd
	437	add r1, r1, #0x110000
	438	ldrb r1, [r1, r0]
	439	bic r0, r0, #1
	440	b s68k_poll_detect
	441
	442
	443	m_s68k_read8_pcm:
	444	tst r0, #0x8000
	445	bne m_read_null
	446
	447	@ must not trash r3 and r12
	448	ldr r1, =Pico
	449	bic r0, r0, #0xff0000
	450	ldr r1, [r1, #OFS_Pico_rom] @ Pico.mcd
	451	mov r2, #0x110000
	452	orr r2, r2, #0x002200
	453	cmp r0, #0x2000
	454	bge m_s68k_read8_pcm_ram
	455	cmp r0, #0x20
	456	movge r0, r0, lsr #1
	457	bge pcd_pcm_read
	458	mov r0, #0
	459	bx lr
	460
	461	m_s68k_read8_pcm_ram:
	462	orr r2, r2, #0x40
	463	ldr r2, [r1, r2]
	464	add r1, r1, #0x100000 @ pcm_ram
	465	and r2, r2, #0x0f000000 @ bank
	466	add r1, r1, r2, lsr #12
	467	bic r0, r0, #0x00e000
	468	mov r0, r0, lsr #1
	469	ldrb r0, [r1, r0]
	470	bx lr
	471
	472
	473	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	474
	475
	476	PicoReadS68k16_dec0: @ 0x080000 - 0x0bffff
	477	mov r3, #0x080000 @ + ^ / 2
	478	b 0f
	479
	480	PicoReadS68k16_dec1:
	481	mov r3, #0x0a0000 @ + ^ / 2
	482	0:
	483	ldr r2, =Pico
	484	eor r0, r0, #2
	485	ldr r2, [r2, #OFS_Pico_rom] @ Pico.mcd
	486	mov r0, r0, lsr #1 @ +4-6 <<16
	487	add r2, r2, r3 @ map to our address
	488	ldrb r0, [r2, r0]
	489	orr r0, r0, r0, lsl #4
	490	bic r0, r0, #0xf0
	491	bx lr
	492
	493
	494	PicoReadS68k16_pr:
	495	and r2, r0, #0xfe00
	496	cmp r2, #0x8000
	497	@ pcm is on 8-bit bus, would this be same as byte access?
	498	bne m_s68k_read8_pcm
	499
	500	m_s68k_read16_regs:
	501	bic r0, r0, #0xff0000
	502	bic r0, r0, #0x008000
	503	bic r0, r0, #0x000001
	504	cmp r0, #8
	505	bne s68k_reg_read16
	506	mov r0, #1
	507	b cdc_host_r
	508
	509
	510	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	511
	512
	513	.macro m_s68k_write8_2M_decode
	514	ldr r2, =Pico
	515	eor r0, r0, #2
	516	ldr r2, [r2, #OFS_Pico_rom] @ Pico.mcd
	517	movs r0, r0, lsr #1 @ +4-6 <<16
	518	add r2, r2, r3 @ map to our address
	519	.endm
	520
	521	PicoWriteS68k8_dec_m2b0: @ overwrite
	522	ands r1, r1, #0x0f
	523	bxeq lr
	524
	525	PicoWriteS68k8_dec_m0b0:
	526	mov r3, #0x080000
	527	b 0f
	528
	529	PicoWriteS68k8_dec_m2b1: @ overwrite
	530	ands r1, r1, #0x0f
	531	bxeq lr
	532
	533	PicoWriteS68k8_dec_m0b1:
	534	mov r3, #0x0a0000
	535	0:
	536	m_s68k_write8_2M_decode
	537	ldrb r0, [r2, r0]!
	538	and r1, r1, #0x0f
	539	movcc r1, r1, lsl #4
	540	andcc r3, r0, #0x0f
	541	andcs r3, r0, #0xf0
	542	orr r3, r3, r1
	543	strneb r3, [r2]
	544	bx lr
	545
	546	PicoWriteS68k8_dec_m1b0: @ underwrite
	547	mov r3, #0x080000
	548	b 0f
	549
	550	PicoWriteS68k8_dec_m1b1:
	551	mov r3, #0x0a0000
	552	0:
	553	ands r1, r1, #0x0f
	554	bxeq lr
	555	m_s68k_write8_2M_decode
	556	ldrb r0, [r2, r0]!
	557	movcc r1, r1, lsl #4
	558	andcc r3, r0, #0x0f
	559	andcs r3, r0, #0xf0
	560	teq r3, r0
	561	bxne lr
	562	orr r3, r3, r1
	563	strneb r3, [r2]
	564	bx lr
	565
	566
	567	PicoWriteS68k8_pr:
	568	and r2, r0, #0xfe00
	569	cmp r2, #0x8000
	570	bne m_s68k_write8_pcm
	571
	572	m_s68k_write8_regs:
	573	bic r0, r0, #0xff0000
	574	bic r0, r0, #0x008000
	575	tst r0, #0x7e00
	576	movne r0, #0
	577	bxne lr
	578	sub r2, r0, #0x59
	579	cmp r2, #0x0f
	580	bhs s68k_reg_write8
	581	bic r0, r0, #1
	582	orr r1, r1, r1, lsl #8
	583	b s68k_reg_write16
	584
	585
	586	m_s68k_write8_pcm:
	587	tst r0, #0x8000
	588	bxne lr
	589	bic r0, r0, #0xff0000
	590	cmp r0, #0x12
	591	movlt r0, r0, lsr #1
	592	blt pcd_pcm_write
	593
	594	cmp r0, #0x2000
	595	bxlt lr
	596
	597	m_s68k_write8_pcm_ram:
	598	ldr r3, =Pico
	599	bic r0, r0, #0x00e000
	600	ldr r3, [r3, #OFS_Pico_rom] @ Pico.mcd
	601	mov r0, r0, lsr #1
	602	add r2, r3, #0x110000
	603	add r2, r2, #0x002200
	604	add r2, r2, #0x000040
	605	ldr r2, [r2]
	606	add r3, r3, #0x100000 @ pcm_ram
	607	and r2, r2, #0x0f000000 @ bank
	608	add r3, r3, r2, lsr #12
	609	strb r1, [r3, r0]
	610	bx lr
	611
	612
	613	@ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	614
	615
	616	.macro m_s68k_write16_2M_decode
	617	ldr r2, =Pico
	618	eor r0, r0, #2
	619	ldr r2, [r2, #OFS_Pico_rom] @ Pico.mcd
	620	mov r0, r0, lsr #1 @ +4-6 <<16
	621	add r2, r2, r3 @ map to our address
	622	.endm
	623
	624	PicoWriteS68k16_dec_m0b0:
	625	mov r3, #0x080000
	626	b 0f
	627
	628	PicoWriteS68k16_dec_m0b1:
	629	mov r3, #0x0a0000
	630	0:
	631	m_s68k_write16_2M_decode
	632	bic r1, r1, #0xf0
	633	orr r1, r1, r1, lsr #4
	634	strb r1, [r2, r0]
	635	bx lr
	636
	637	PicoWriteS68k16_dec_m1b0: @ underwrite
	638	mov r3, #0x080000
	639	b 0f
	640
	641	PicoWriteS68k16_dec_m1b1:
	642	mov r3, #0x0a0000
	643	0:
	644	bics r1, r1, #0xf000
	645	bicnes r1, r1, #0x00f0
	646	bxeq lr
	647	orr r1, r1, r1, lsr #4
	648	m_s68k_write16_2M_decode
	649	ldrb r0, [r2, r0]!
	650	and r3, r1, #0x0f
	651	and r1, r1, #0xf0
	652	tst r0, #0x0f
	653	orreq r0, r0, r3
	654	tst r0, #0xf0
	655	orreq r0, r0, r1
	656	strb r0, [r2]
	657	bx lr
	658
	659	PicoWriteS68k16_dec_m2b0: @ overwrite
	660	mov r3, #0x080000
	661	b 0f
	662
	663	PicoWriteS68k16_dec_m2b1:
	664	mov r3, #0x0a0000
	665	0:
	666	bics r1, r1, #0xf000
	667	bicnes r1, r1, #0x00f0
	668	bxeq lr
	669	orr r1, r1, r1, lsr #4
	670	m_s68k_write16_2M_decode
	671	ldrb r0, [r2, r0]!
	672	ands r3, r1, #0x0f
	673	andne r0, r0, #0xf0
	674	orrne r0, r0, r3
	675	ands r1, r1, #0xf0
	676	andne r0, r0, #0x0f
	677	orrne r0, r0, r1
	678	strb r0, [r2]
	679	bx lr
	680
	681
	682	PicoWriteS68k16_pr:
	683	and r2, r0, #0xfe00
	684	cmp r2, #0x8000
	685	bne m_s68k_write8_pcm
	686
	687	m_s68k_write16_regs:
	688	bic r0, r0, #0xff0000
	689	bic r0, r0, #0x008000
	690	bic r0, r0, #1
	691	tst r0, #0x7e00
	692	movne r0, #0
	693	bxne lr
	694	cmp r0, #0x0e
	695	bne s68k_reg_write16
	696
	697	m_s68k_write16_regs_spec: @ special case
	698	ldr r2, =Pico
	699	mov r0, #0x110000
	700	ldr r2, [r2, #OFS_Pico_rom] @ Pico.mcd
	701	add r0, r0, #0x00000f
	702	strb r1, [r2, r0] @ if (a == 0xe) s68k_regs[0xf] = d;
	703	bx lr
	704
	705	.pool
	706
	707	@ vim:filetype=armasm