z180/msgbuf-a.180

   1         page    255
   2         .z80
   3
   4         global  mrx.fifo,mtx.fifo
   5
   6         global  msginit,msgi.st,msg.in,msgo.st,msg.out
   7         global  msg.sout
   8
   9         extrn   buf.init
  10
  11         include config.inc
  12         include z180reg.inc
  13
  14 ;--------------------------------------------------------------
  15
  16         dseg
  17
  18         mkbuf   mrx.fifo,mrx.fifo_len
  19         mkbuf   mtx.fifo,mtx.fifo_len
  20
  21 ;--------------------------------------------------------------
  22
  23         cseg
  24
  25 ;
  26 ; Init buffer
  27 ;
  28
  29 msginit:
  30         ld      ix,mrx.fifo
  31         ld      a,mrx.fifo.mask
  32         call    buf.init
  33         ld      ix,mtx.fifo
  34         ld      a,mtx.fifo.mask
  35         jp      buf.init
  36
  37 ;--------------------------------------------------------------
  38
  39 msgi.st:
  40         push    ix
  41         ld      ix,mrx.fifo             ;
  42
  43 buf.empty:
  44         ld      a,(ix+o.in_idx)         ;
  45         sub     (ix+o.out_idx)          ;
  46         pop     ix
  47         ret     z
  48         or      0ffh
  49         ret
  50
  51 ;--------------------------------------------------------------
  52
  53 msg.in:
  54         push    ix
  55         ld      ix,mrx.fifo             ;
  56
  57 buf.get:
  58         ld      a,(ix+o.out_idx)        ;
  59 bg.wait:
  60         cp      (ix+o.in_idx)           ;
  61         jr      z,bg.wait
  62
  63         push    hl                      ;
  64         push    ix
  65         pop     hl
  66         add     a,l
  67         ld      l,a
  68         jr      nc,bg.nc
  69         inc     h
  70 bg.nc:
  71         ld      l,(hl)
  72
  73         ld      a,(ix+o.out_idx)        ;
  74         inc     a
  75         and     (ix+o.mask)
  76         ld      (ix+o.out_idx),a
  77
  78         ld      a,l
  79         pop     hl
  80         pop     ix
  81         ret
  82
  83 ;--------------------------------------------------------------
  84
  85 msgo.st:
  86         push    ix
  87         ld      ix,mtx.fifo             ;
  88
  89 buf.full:
  90         ld      a,(ix+o.in_idx)         ;
  91         inc     a
  92         and     (ix+o.mask)
  93         sub     (ix+o.out_idx)          ;
  94         pop     ix
  95         ret     z
  96         or      0ffh
  97         ret
  98
  99 ;--------------------------------------------------------------
 100
 101 msg.out:
 102         push    ix
 103         ld      ix,mtx.fifo             ;
 104
 105 buf.put:
 106         push    hl                      ;
 107         push    bc
 108         push    ix
 109         pop     hl
 110         ld      c,(ix+o.in_idx)         ;
 111         ld      b,0
 112         add     hl,bc
 113         ld      b,a
 114
 115         ld      a,c                     ;
 116         inc     a
 117         and     (ix+o.mask)
 118 bp.wait:
 119         cp      (ix+o.out_idx)          ;
 120         jr      z,bp.wait
 121         ld      (hl),b
 122         ld      (ix+o.in_idx),a
 123
 124         ld      a,b
 125         out0    (AVRINT5),a
 126         pop     bc
 127         pop     hl
 128         pop     ix
 129         ret
 130
 131
 132 ;--------------------------------------------------------------
 133 ;
 134 ; (hl): data
 135
 136 msg.sout:
 137         push    ix
 138         ld      ix,mtx.fifo             ;
 139
 140         push    bc
 141         push    de
 142         ld      b,(hl)                  ;
 143         inc     hl
 144         ex      de,hl
 145
 146 ms.ol:
 147         push    ix
 148         pop     hl
 149         ld      c,(ix+o.in_idx)         ;
 150         ld      a,c
 151         add     l
 152         ld      l,a
 153         jr      nc,ms.on
 154         inc     h
 155 ms.on:
 156         ld      a,c                     ;
 157         inc     a
 158         and     (ix+o.mask)
 159 ms.wait:
 160         cp      (ix+o.out_idx)          ;
 161         jr      z,ms.wait
 162         ld      c,a
 163         ld      a,(de)
 164         inc     de
 165         ld      (hl),a
 166         ld      (ix+o.in_idx),c
 167         djnz    ms.ol
 168         out0    (AVRINT5),a
 169         ex      de,hl
 170         pop     de
 171         pop     bc
 172         pop     ix
 173         ret
 174
 175 ;--------------------------------------------------------------
 176
 177 msg.co:
 178         push    af
 179         push    hl
 180         ld      (buf_char),a
 181         ld      hl,buf
 182         call    msg.sout
 183         pop     hl
 184         pop     af
 185         ret
 186
 187
 188 buf:
 189         db      buf_end - $ - 1         ;output string length
 190         db      0AEh                    ; message start token
 191         db      buf_end - $ - 1         ; message length
 192         db      1                       ; command
 193         db      1                       ; subcommand
 194 buf_char:
 195         db      0                       ; pay load
 196 buf_end:
 197
 198 ;----------------------------------------------------------------------
 199
 200         end
 201