avrcpm/avr/dram-4bit.inc

   1 ; DRAM interface for *one* 256K x 4 bit DRAM chip.
   2 ; This is part of the Z80-CP/M emulator written by Sprite_tm.
   3
   4 ;    Copyright (C) 2010 Sprite_tm
   5 ;    Copyright (C) 2010 Leo C.
   6
   7 ;    This file is part of avrcpm.
   8 ;
   9 ;    avrcpm is free software: you can redistribute it and/or modify it
  10 ;    under the terms of the GNU General Public License as published by
  11 ;    the Free Software Foundation, either version 3 of the License, or
  12 ;    (at your option) any later version.
  13 ;
  14 ;    avrcpm is distributed in the hope that it will be useful,
  15 ;    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;    GNU General Public License for more details.
  18 ;
  19 ;    You should have received a copy of the GNU General Public License
  20 ;    along with avrcpm.  If not, see <http://www.gnu.org/licenses/>.
  21 ;
  22 ;    $Id$
  23 ;
  24
  25
  26 ; -------------------- DRAM  macros---------------
  27
  28 ; add wait states
  29 ;       dram_wait  number_of_cycles
  30
  31 .macro dram_wait
  32 .if @0 > 1
  33         rjmp    PC+1
  34         dram_wait @0 - 2
  35 .elif @0 > 0
  36         nop
  37         dram_wait @0 - 1
  38 .endif
  39 .endm
  40
  41 ; ------------------------------------------------
  42
  43 ; DRAM_SETADDR val, low_and_mask, low_or_mask, high_and_mask, high_or_mask
  44
  45 .macro DRAM_SETADDR
  46         mov temp,@0
  47 .if low(@1) != 0xff
  48         andi temp,@1
  49 .endif
  50 .if  low(@2) != 0
  51         ori temp, @2
  52 .endif
  53         out P_AL,temp
  54
  55         mov temp,@0
  56 .if low(@3) != 0xff
  57         andi temp,@3
  58 .endif
  59         ori temp, @4 | (1<<mmc_cs)
  60         out P_AH,temp
  61 .endm
  62
  63
  64 ;----------------------------------------------
  65 ; Read byte from DRAM
  66 ;       temp = destreg, xh = memaddrh, xl = memaddrl
  67
  68 .macro  mem_read
  69         rcall   dram_read
  70 .endm
  71
  72 ;----------------------------------------------
  73 ; Read byte from DRAM
  74 ;       mem_read  memaddr
  75 ;       temp = destreg
  76
  77 .macro  mem_read_s
  78         movw    xl,@0l
  79         rcall   dram_read
  80 .endm
  81
  82 ;----------------------------------------------
  83 ; Read byte from DRAM
  84 ;       mem_read  destreg
  85 ;       xh = memaddrh, xl = memaddrl
  86
  87 .macro  mem_read_d
  88         lcall   dram_read
  89         mov     @0,temp
  90 .endm
  91
  92 ;----------------------------------------------
  93 ; Read byte from DRAM
  94 ;       mem_read  destreg, memaddr
  95
  96 .macro  mem_read_ds
  97         movw    xl,@1l
  98         lcall   dram_read
  99         mov     @0,temp
 100 .endm
 101
 102 ;----------------------------------------------
 103 ; Write byte to DRAM
 104 ;       xh = memaddrh, xl = memaddrl, temp = srcreg
 105
 106 .macro  mem_write
 107         lcall   dram_write
 108 .endm
 109
 110 ;----------------------------------------------
 111 ; Write byte to DRAM
 112 ;       temp = srcreg
 113 ;       mem_write  memaddr
 114
 115 .macro  mem_write_d
 116         movw    x,@0l
 117         rcall   dram_write
 118 .endm
 119
 120 ;----------------------------------------------
 121 ; Write byte to DRAM
 122 ;       xh = memaddrh, xl = memaddrl
 123 ;       mem_write  sourcereg
 124
 125 .macro  mem_write_s
 126         mov     temp,@0
 127         lcall   dram_write
 128 .endm
 129
 130 ;----------------------------------------------
 131 ; Write byte to DRAM
 132 ;       mem_write  memaddr, sourcereg
 133
 134 .macro  mem_write_ds
 135         movw    x,@0l
 136         mov     temp,@1
 137         lcall   dram_write
 138 .endm
 139
 140