path: root/z80.cpu

info
	prefix z80_
	opcode_size 8
	extra_tables cb ed dded fded dd fd
	body z80_run_op
	include z80_util.c
	header z80.h
	
regs
	main 8 b c d e h l f a
	alt 8 b' c' d' e' h' l' f' a'
	i 8
	r 8
	iff1 8
	iff2 8
	imode 8
	sp 16
	ix 16
	iy 16
	pc 16
	wz 16
	nflag 8
	last_flag_result 8
	pvflag 8
	chflags 8
	zflag 8
	scratch1 16
	scratch2 16
	
flags
	register f
	S 7 sign last_flag_result.7
	Z 6 zero zflag
	Y 5 bit-5 last_flag_result.5
	H 4 half-carry chflags.3
	P 2 parity pvflag
	V 2 overflow pvflag
	X 3 bit-3 last_flag_result.3
	N 1 none nflag
	C 0 carry chflags.7

	
z80_op_fetch
	cycles 1
	add 1 r r
	mov pc scratch1
	ocall read_8
	add 1 pc pc
	
z80_run_op
	z80_op_fetch
	dispatch scratch1
	
11001011 cb_prefix
	z80_op_fetch
	dispatch scratch1 cb

11011101 dd_prefix
	z80_op_fetch
	dispatch scratch1 dd

11101101 ed_prefix
	z80_op_fetch
	dispatch scratch1 ed

11111101 fd_prefix
	z80_op_fetch
	dispatch scratch1 fd
	
z80_check_cond
	arg cond 8
	local invert 8
	switch cond
	case 0
	meta istrue invert
	lnot zflag invert
	
	case 1
	meta istrue zflag
	
	case 2
	meta istrue invert
	not chflags invert
	and 0x80 invert invert
	
	case 3
	meta istrue invert
	and 0x80 invert invert
	
	case 4
	meta istrue invert
	lnot pvflag invert
	
	case 5
	meta istrue pvflag
	
	case 6
	meta istrue invert
	not last_flag_result invert
	and 0x80 invert invert
	
	case 7
	meta istrue invert
	and 0x80 last_flag_result invert
	
	end
	
z80_fetch_hl
	lsl h 8 scratch1
	or l scratch1 scratch1
	ocall read_8
	
z80_store_hl
	lsl h 8 scratch2
	or l scratch2 scratch2
	ocall write_8

z80_fetch_immed
	mov pc scratch1
	ocall read_8
	add 1 pc pc
	
z80_fetch_immed16
	mov pc scratch1
	ocall read_8
	mov scratch1 wz
	add 1 pc pc
	mov pc scratch1
	ocall read_8
	add 1 pc pc
	lsl scratch1 8 scratch1
	or scratch1 wz wz

z80_fetch_immed_reg16
	mov pc scratch1
	ocall read_8
	mov scratch1 low
	add 1 pc pc
	mov pc scratch1
	ocall read_8
	mov scratch1 high
	add 1 pc pc
	
z80_fetch_immed_to_reg16
	mov pc scratch1
	ocall read_8
	mov scratch1 reg
	add 1 pc pc
	mov pc scratch1
	ocall read_8
	add 1 pc pc
	lsl scratch1 8 scratch1
	or scratch1 reg reg
	
z80_calc_index
	z80_fetch_immed
	add scratch1 index wz
	cycles 5
	
z80_fetch_index
	z80_calc_index
	mov wz scratch1
	ocall read_8

z80_fetch_ix
	meta index ix
	z80_fetch_index

z80_fetch_iy
	meta index iy
	z80_fetch_index

01RRR110 ld_from_hl
	z80_fetch_hl
	mov scratch1 main.R

01DDDSSS ld_from_reg
	mov main.S main.D
	
dd 01RRR110 ld_from_ix
	z80_fetch_ix
	mov scratch1 main.R

fd 01RRR110 ld_from_iy
	z80_fetch_iy
	mov scratch1 main.R

00RRR110 ld_immed
	z80_fetch_immed
	mov scratch1 main.R

01110RRR ld_to_hl
	mov main.R scratch1
	z80_store_hl

dd 01110RRR ld_to_ix
	meta index ix
	z80_calc_index
	mov wz scratch2
	mov main.R scratch1
	ocall write_8

fd 01110RRR ld_to_iy
	meta index iy
	z80_calc_index
	mov wz scratch2
	mov main.R scratch1
	ocall write_8

00110110 ld_to_hl_immed
	z80_fetch_immed
	z80_store_hl

00001010 ld_a_from_bc
	lsl b 8 scratch1
	or c scratch2 scratch1
	ocall read_8
	mov scratch1 a

00011010 ld_a_from_de
	lsl d 8 scratch1
	or e scratch2 scratch1
	ocall write_8
	mov scratch1 a

00111010 ld_a_from_immed
	z80_fetch_immed16
	mov wz scratch1
	ocall read_8
	mov scratch1 a
	
00000010 ld_a_to_bc
	lsl b 8 scratch2
	or c scratch2 scratch2
	mov a scratch1
	ocall write_8
	
00010010 ld_a_to_de
	lsl d 8 scratch2
	or e scratch2 scratch2
	mov a scratch1
	ocall write_8

00110010 ld_a_to_immed
	z80_fetch_immed16
	mov wz scratch2
	mov a scratch1
	ocall write_8

ed 01000111 ld_i_a
	mov a i
	cycles 1

ed 01001111 ld_r_a
	mov a r
	cycles 1

00000001 ld_bc_immed
	meta high b
	meta low c
	z80_fetch_immed_reg16

00010001 ld_de_immed
	meta high d
	meta low e
	z80_fetch_immed_reg16

00100001 ld_hl_immed
	meta high h
	meta low l
	z80_fetch_immed_reg16

00110001 ld_sp_immed
	meta reg sp
	z80_fetch_immed_to_reg16

dd 00100001 ld_ix_immed
	meta reg ix
	z80_fetch_immed_to_reg16

fd 00100001 ld_iy_immed
	meta reg iy
	z80_fetch_immed_to_reg16
	
z80_fetch16_from_immed
	z80_fetch_immed16
	mov wz scratch1
	ocall read_8
	mov scratch1 low
	add 1 wz wz
	mov wz scratch1
	ocall read_8
	mov scratch1 high

00101010 ld_hl_from_immed
	meta low l
	meta high h
	z80_fetch16_from_immed

ed 01001011 ld_bc_from_immed
	meta low c
	meta high b
	z80_fetch16_from_immed

ed 01011011 ld_de_from_immed
	meta low e
	meta high c
	z80_fetch16_from_immed

ed 01101011 ld_hl_from_immed_slow
	meta low l
	meta high h
	z80_fetch16_from_immed
	
z80_fetch_reg16_from_immed
	z80_fetch_immed16
	mov wz scratch1
	ocall read_8
	mov scratch1 reg
	add 1 wz wz
	mov wz scratch1
	ocall read_8
	lsl scratch1 8 scratch1
	or scratch1 reg reg

ed 01111011 ld_sp_from_immed
	meta reg sp
	z80_fetch_reg16_from_immed

dd 00101010 ld_ix_from_immed
	meta reg ix
	z80_fetch_reg16_from_immed

fd 00101010 ld_iy_from_immed
	meta reg iy
	z80_fetch_reg16_from_immed

00100010 ld_hl_to_immed
	z80_fetch_immed16
	mov wz scratch2
	mov l scratch1
	ocall write_8
	add 1 wz wz
	mov wz scratch2
	mov h scratch1
	ocall write_8
	
z80_regpair_to_immed
	z80_fetch_immed16
	mov wz scratch2
	mov low scratch1
	ocall write_8
	add 1 wz wz
	mov high scratch1
	mov wz scratch2
	ocall write_8
	
ed 01000011 ld_bc_to_immed
	meta low c
	meta high b
	z80_regpair_to_immed

ed 01010011 ld_de_to_immed
	meta low e
	meta high d
	z80_regpair_to_immed
	
ed 01100011 ld_hl_to_immed_slow
	meta low l
	meta high h
	z80_regpair_to_immed
	
ed 01110011 ld_sp_to_immed
	meta low sp
	local sph 8
	lsr sp 8 sph
	meta high sph
	z80_regpair_to_immed

11111001 ld_sp_hl
	cycles 2
	lsl h 8 sp
	or l sp sp
	mov wz scratch2
	mov sp scratch1
	ocall write_8
	add 1 wz wz
	lsr sp 8 scratch1
	mov wz scratch2
	ocall write_8

z80_push
	cycles 1
	sub 1 sp sp
	mov sp scratch2
	mov high scratch1
	ocall write_8
	sub 1 sp sp
	mov sp scratch2
	mov low scratch1
	ocall write_8

11000101 push_bc
	meta high b
	meta low c
	z80_push

11010101 push_de
	meta high d
	meta low e
	z80_push

11100101 push_hl
	meta high h
	meta low l
	z80_push

11110101 push_af
	meta high a
	meta low f
	z80_push
	
dd 11100101 push_ix
	local ixh 8
	lsr ix 8 ixh
	meta high ixh
	meta low ix
	z80_push

fd 11100101 push_iy
	local iyh 8
	lsr iy 8 iyh
	meta high iyh
	meta low iy
	z80_push

z80_pop
	mov sp scratch1
	ocall read_8
	add 1 sp sp
	mov scratch1 low
	mov sp scratch1
	ocall read_8
	add 1 sp sp
	mov scratch1 high

11000001 pop_bc
	meta high b
	meta low c
	z80_pop

11010001 pop_de
	meta high d
	meta low e
	z80_pop

11100001 pop_hl
	meta high h
	meta low l
	z80_pop

11110001 pop_af
	meta high a
	meta low f
	z80_pop

dd 11100001 pop_ix
	local ixh 16
	meta high ixh
	meta low ix
	z80_pop
	lsl ixh 8 ixh
	or ixh ix ix

fd 11100001 pop_iy
	local iyh 16
	meta high iyh
	meta low iy
	z80_pop
	lsl iyh 8 iyh
	or iyh iy iy

11101011 ex_de_hl
	xchg e l
	xchg d h

00001000 ex_af_af
	xchg a a'
	xchg f f'

11011001 exx
	xchg b b'
	xchg c c'
	xchg d d'
	xchg e e'
	xchg h h'
	xchg l l'

11100011 ex_sp_hl
	mov sp scratch1
	ocall read_8
	xchg l scratch1
	cycles 1
	mov sp scratch2
	ocall write_8
	add 1 sp wz
	mov wz scratch2
	ocall read_8
	xchg h scratch1
	cycles 2
	mov wz scratch2
	ocall write_8

10000RRR add_reg
	add a main.R a
	update_flags SZYHVXN0C
	
10000110 add_hl
	z80_fetch_hl
	add a scratch1 a
	update_flags SZYHVXN0C

11000110 add_immed
	z80_fetch_immed
	add a scratch1 a
	update_flags SZYHVXN0C
	
10001RRR adc_reg
	adc a main.R a
	update_flags SZYHVXN0C

10001110 adc_hl
	z80_fetch_hl
	adc a scratch1 a
	update_flags SZYHVXN0C

11001110 adc_immed
	z80_fetch_immed
	adc a scratch1 a
	update_flags SZYHVXN0C

10010RRR sub_reg
	sub main.R a a
	update_flags SZYHVXN1C
	
10010110 sub_hl
	z80_fetch_hl
	sub scratch1 a a
	update_flags SZYHVXN1C

11010110 sub_immed
	z80_fetch_immed
	sub scratch1 a a
	update_flags SZYHVXN1C

10011RRR sbc_reg
	sbc main.R a a
	update_flags SZYHVXN1C
	
10011110 sbc_hl
	z80_fetch_hl
	sbc scratch1 a a
	update_flags SZYHVXN1C

11011110 sbc_immed
	z80_fetch_immed
	sbc scratch1 a a
	update_flags SZYHVXN1C

10100RRR and_reg
	and a main.R a
	update_flags SZYH1PXN0C0
	
10100110 and_hl
	z80_fetch_hl
	and a scratch1 a
	update_flags SZYH1PXN0C0

11100110 and_immed
	z80_fetch_immed
	and a scratch1 a
	update_flags SZYH1PXN0C0
	
10110RRR or_reg
	or a main.R a
	update_flags SZYH0PXN0C0
	
10110110 or_hl
	z80_fetch_hl
	or a scratch1 a
	update_flags SZYH0PXN0C0

11110110 or_immed
	z80_fetch_immed
	or a scratch1 a
	update_flags SZYH0PXN0C0
	
10101RRR xor_reg
	xor a main.R a
	update_flags SZYH0PXN0C0
	
10101110 xor_hl
	z80_fetch_hl
	xor a scratch1 a
	update_flags SZYH0PXN0C0

11101110 xor_immed
	z80_fetch_immed
	xor a scratch1 a
	update_flags SZYH0PXN0C0

10111RRR cp_reg
	cmp main.R a
	update_flags SZYHVXN1C
	
10111110 cp_hl
	z80_fetch_hl
	cmp scratch1 a
	update_flags SZYHVXN1C

11111110 cp_immed
	z80_fetch_immed
	cmp scratch1 a
	update_flags SZYHVXN1C

00RRR100 inc_reg
	add 1 main.R main.R
	update_flags SZYHVXN0
	
00110100 inc_hl
	z80_fetch_hl
	#TODO: fix size
	add 1 scratch1 scratch1
	update_flags SZYHVXN0
	z80_store_hl

00RRR101 dec_reg
	add 1 main.R main.R
	update_flags SZYHVXN0
	
00110101 dec_hl
	z80_fetch_hl
	#TODO: fix size
	add 1 scratch1 scratch1
	update_flags SZYHVXN0
	z80_store_hl

00101111 cpl
	not a a
	update_flags YH1XN1

11101101 neg
	neg a a
	update_flags SZYHVXN1C

00111111 ccf
	xor 0x80 chflags chflags

00111111 scf
	or 0x80 chflags chflags

00000000 nop

11110011 di
	mov 0 iff1
	mov 0 iff2
	#TODO: update interrupt/sync cycle

11111011 ei
	mov 1 iff1
	mov 1 iff2
	#TODO: update interrupt/sync cycle

ed 01000110 im0
	mov 0 imode

ed 01010110 im1
	mov 1 imode

ed 01011110 im2
	mov 2 imode
	
11000011 jp
	z80_fetch_immed16
	mov wz pc
	
11CCC010 jp_cc
	z80_check_cond C
	z80_fetch_immed16
	if istrue
	
	mov wz pc
	
	end
	
00011000 jr
	z80_fetch_immed
	#TODO: determine if this updates wz
	sext 16 scratch1 scratch1
	add scratch1 pc pc
	cycles 5
	
001CC000 jr_cc
	z80_check_cond C
	z80_fetch_immed
	
	if istrue
	
	sext 16 scratch1 scratch1
	add scratch1 pc pc
	cycles 5
	
	end
	
00010000 djnz
	cycles 1
	z80_fetch_immed
	sub 1 b b
	
	if b
	
	sext 16 scratch1 scratch1
	add scratch1 pc pc
	cycles 5
	
	end
	

11001101 call_uncond
	z80_fetch_immed16
	local pch 8
	lsr pc 8 pch
	meta high pch
	meta low pc
	z80_push
	mov wz pc
	
11TTT111 rst
	local pch 8
	lsr pc 8 pch
	meta high pch
	meta low pc
	z80_push
	lsl T 3 scratch1
	mov scratch1 pc

11001001 ret
	#TODO: confirm this goes through wz
	local wzh 16
	meta high wzh
	meta low wz
	z80_pop
	lsl wzh 8 wzh
	or wzh wz wz
	mov wz pc

11011011 in_abs
	z80_fetch_immed
	ocall io_read8
	mov scratch1 a
	
ed 01RRR000 in_bc
	lsl b 8 scratch1
	or c scratch1 scratch1
	ocall io_read8
	mov scratch1 main.R
	
11010011 out_abs
	z80_fetch_immed
	mov scratch1 scratch2
	mov a scratch1
	ocall io_write8
	
ed 01RRR001 out_bc
	lsl b 8 scratch2
	or c scratch2 scratch2
	mov main.R scratch1
	ocall io_write8