[avrcpm.git] / dram-8bit.inc

; DRAM interface for 2 RAM chips. Supports up to 4 Mbyte of DRAM.
; This is part of the Z80-CP/M emulator written by Sprite_tm.

;    Copyright (C) 2010 Leo C.

;    This file is part of avrcpm.
;
;    avrcpm is free software: you can redistribute it and/or modify it
;    under the terms of the GNU General Public License as published by
;    the Free Software Foundation, either version 3 of the License, or
;    (at your option) any later version.
;
;    avrcpm is distributed in the hope that it will be useful,
;    but WITHOUT ANY WARRANTY; without even the implied warranty of
;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;    GNU General Public License for more details.
;
;    You should have received a copy of the GNU General Public License
;    along with avrcpm.  If not, see <http://www.gnu.org/licenses/>.
;
;    $Id$
;


; -------------------- DRAM  macros---------------

; add wait states
;	dram_wait  number_of_cycles

.macro dram_wait
.if @0 > 1
	rjmp	PC+1
	dram_wait @0 - 2
.elif @0 > 0
	nop
	dram_wait @0 - 1
.endif
.endm

;----------------------------------------------
; Read byte from DRAM
;	mem_read_ds  destreg, memaddr

.macro	mem_read_ds
	cli				;1
	out	PORTD,@1h		;1
	out	PORTC,_RAS0		;1
	out	PORTD,@1l		;1
	out	PORTC,_CAS0		;1
	out	DDRD,_0			;1
	out	PORTC,_OE		;1
	rjmp	PC+1			;2
	dram_wait DRAM_WAITSTATES	;
	in	@0,PIND			;1
	out	PORTC,_255		;1
	sei				;1
	out	DDRD,_255		;1  = 14 + DRAM_WAITSTATES
.endm

;----------------------------------------------
; Read byte from DRAM
;	mem_read_d  destreg
;  	x = memaddr

.macro	mem_read_d
	mem_read_ds  @0, x
.endm

;----------------------------------------------
; Read byte from DRAM
;	mem_read_s  memaddr
;  	temp = destreg

.macro	mem_read_s
	mem_read_ds  temp, @0
.endm

;----------------------------------------------
; Read byte from DRAM
;	mem_read
;  	temp = destreg, x = memaddr

.macro	mem_read
	mem_read_ds  temp, x
.endm

;----------------------------------------------
; Write byte to DRAM
;	mem_write_ds  memaddr, sourcereg

.macro	mem_write_ds
	cli				;1
	out	PORTD,@0h		;1
	out	PORTC,_RAS0		;1
	out	PORTD,@0l		;1
	out	PORTC,_CAS0		;1
	out	PORTD,@1		;1
	out	PORTC,_WE		;1
	sei				;1
	out	PORTC,_255		;1  = 9
.endm

;----------------------------------------------
; Write byte to DRAM
;	mem_write_d  memaddr
;  	temp = srcreg

.macro	mem_write_d
	mem_write_ds @0, temp	
.endm

;----------------------------------------------
; Write byte to DRAM
;	mem_write_s  sourcereg
;  	xh = memaddrh, xl = memaddrl

.macro	mem_write_s
	mem_write_ds x, @0	
.endm

;----------------------------------------------
; Write byte to DRAM
;	mem_write
;  	xh = memaddrh, xl = memaddrl, temp = srcreg

.macro	mem_write
	mem_write_ds x, temp
.endm
Commit	Line	Data
f0d2aa0e L	1	; DRAM interface for 2 RAM chips. Supports up to 4 Mbyte of DRAM.
	2	; This is part of the Z80-CP/M emulator written by Sprite_tm.
	3
	4	; Copyright (C) 2010 Leo C.
	5
	6	; This file is part of avrcpm.
	7	;
	8	; avrcpm is free software: you can redistribute it and/or modify it
	9	; under the terms of the GNU General Public License as published by
	10	; the Free Software Foundation, either version 3 of the License, or
	11	; (at your option) any later version.
	12	;
	13	; avrcpm is distributed in the hope that it will be useful,
	14	; but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	; GNU General Public License for more details.
	17	;
	18	; You should have received a copy of the GNU General Public License
	19	; along with avrcpm. If not, see <http://www.gnu.org/licenses/>.
	20	;
	21	; $Id$
	22	;
	23
	24
	25	; -------------------- DRAM macros---------------
	26
	27	; add wait states
	28	; dram_wait number_of_cycles
	29
	30	.macro dram_wait
	31	.if @0 > 1
	32	rjmp PC+1
	33	dram_wait @0 - 2
	34	.elif @0 > 0
	35	nop
	36	dram_wait @0 - 1
	37	.endif
	38	.endm
	39
	40	;----------------------------------------------
	41	; Read byte from DRAM
	42	; mem_read_ds destreg, memaddr
	43
	44	.macro mem_read_ds
	45	cli ;1
	46	out PORTD,@1h ;1
	47	out PORTC,_RAS0 ;1
	48	out PORTD,@1l ;1
	49	out PORTC,_CAS0 ;1
	50	out DDRD,_0 ;1
	51	out PORTC,_OE ;1
	52	rjmp PC+1 ;2
	53	dram_wait DRAM_WAITSTATES ;
	54	in @0,PIND ;1
	55	out PORTC,_255 ;1
	56	sei ;1
	57	out DDRD,_255 ;1 = 14 + DRAM_WAITSTATES
	58	.endm
	59
	60	;----------------------------------------------
	61	; Read byte from DRAM
	62	; mem_read_d destreg
	63	; x = memaddr
	64
65	.macro mem_read_d
66	mem_read_ds @0, x
67	.endm
68
69	;----------------------------------------------
70	; Read byte from DRAM
71	; mem_read_s memaddr
72	; temp = destreg
73
74	.macro mem_read_s
75	mem_read_ds temp, @0
76	.endm
77
78	;----------------------------------------------
79	; Read byte from DRAM
80	; mem_read
81	; temp = destreg, x = memaddr
82
83	.macro mem_read
84	mem_read_ds temp, x
85	.endm
86
87	;----------------------------------------------
88	; Write byte to DRAM
89	; mem_write_ds memaddr, sourcereg
90
91	.macro mem_write_ds
92	cli ;1
93	out PORTD,@0h ;1
94	out PORTC,_RAS0 ;1
95	out PORTD,@0l ;1
96	out PORTC,_CAS0 ;1
97	out PORTD,@1 ;1
98	out PORTC,_WE ;1
99	sei ;1
100	out PORTC,_255 ;1 = 9
101	.endm
102
103	;----------------------------------------------
104	; Write byte to DRAM
105	; mem_write_d memaddr
106	; temp = srcreg
107
108	.macro mem_write_d
109	mem_write_ds @0, temp
110	.endm
111
112	;----------------------------------------------
113	; Write byte to DRAM
114	; mem_write_s sourcereg
115	; xh = memaddrh, xl = memaddrl
116
117	.macro mem_write_s
118	mem_write_ds x, @0
119	.endm
120
121	;----------------------------------------------
122	; Write byte to DRAM
123	; mem_write
124	; xh = memaddrh, xl = memaddrl, temp = srcreg
125
126	.macro mem_write
127	mem_write_ds x, temp
128	.endm
129
130