view notes.txt @ 660:e7cae6d9aaa6

Add the 3 cycle delay back in to Z80 bank area access
author Michael Pavone <pavone@retrodev.com>
date Thu, 01 Jan 2015 22:18:32 -0800
parents 0ae589d4c3f9
children
line wrap: on
line source

cmp.w <ea>, Dn 4(1/0) + <ea> time
cmp.l <ea>, Dn 6(1/0) + <ea> time
cmp.w #num, Dn 4(1/0) + 4(1/0)
cmp.l #num, Dn 6(1/0) + 8(2/0)

cmpi.w #num, Dn 8(2/0)
cmpi.l #num, Dn 14(3/0)


movem

subtype field (bits 9-11) = 110 or 100 depending on direction
bit 8 = 0
bit 7 = 1
bit 6 = size



x86-64 registers in 68K core

1. native stack pointer
2. current cycle count
3. target cycle count
4. cartridge address
5. work ram address
6. scratch register
7. context pointer (contains 68K registers and memory pointers not in registers)
8. status register (maybe, depends on how well I can abuse native x86 status stuff)
Rest of registers used for holding 68K registers

rax = cycle counter
bl = N flag
bh = V flag
rcx = scratch register
dl = Z flag
dh = C flag
rbp = target cycle count
rsi = context pointer
rdi = scratch register
r8 = cartridge address
r9 = work ram address
r10 = d0
r11 = d1
r12 = d2
r13 = a0
r14 = a1
r15 = a7
rsp = native stack pointer

68K context:
uint8_t flags[5];
uint8_t pad??[3]
uint32_t dregs[8]; //8 + 4 * reg
uint32_t aregs[8]; //40 + 4 * reg
.....

x86-64 registers in Z80 core

ax = HL
bx = BC
cx = DE
dx = IX
ebp = current cycle count
rsi = context pointer
edi = target cycle count
rsp = native stack pointer
r8 = IY
r9 = SP
r10 = A (maybe AF?)
r11 = z80 ram address
r12 = cartridge address if bank is pointed at ROM
r13 = scratch1
r14 = scratch2
r15 = ?maybe z80 bank register?