z180/conbuf-a.180

   1         page    255
   2         .z80
   3
   4 ;
   5 ; FIFO channels for communication with avr
   6 ;
   7         global  ff.init,ff.in,ff.out,ff.i.st
   8
   9         extrn   buf.init
  10
  11         include config.inc
  12         include z180reg.inc
  13
  14
  15 ;--------------------------------------------------------------
  16
  17         dseg
  18
  19
  20         mkbuf   co.fifo,co.fifo_len
  21         mkbuf   ci.fifo,ci.fifo_len
  22
  23
  24 ;--------------------------------------------------------------
  25
  26         cseg
  27
  28 ; Init Serial I/O for console input and output
  29 ;
  30
  31 ff.init:
  32         ld      ix,ci.fifo
  33         ld      a,ci.fifo.mask
  34         call    buf.init
  35         ld      ix,co.fifo
  36         ld      a,co.fifo.mask
  37         jp      buf.init
  38
  39
  40 ff.i.st:
  41         push    ix
  42         ld      ix,ci.fifo              ;
  43
  44 buf.empty:
  45         ld      a,(ix+o.in_idx)         ;
  46         sub     (ix+o.out_idx)          ;
  47         pop     ix
  48         ret     z
  49         or      0ffh
  50         ret
  51
  52
  53 ff.in:
  54         push    ix
  55         ld      ix,ci.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 ff.o.st:
  85         push    ix
  86         ld      ix,co.fifo              ;
  87
  88 buf.full:
  89         ld      a,(ix+o.in_idx)         ;
  90         inc     a
  91         and     (ix+o.mask)
  92         sub     (ix+o.out_idx)          ;
  93         pop     ix
  94         ret     z
  95         or      0ffh
  96         ret
  97
  98
  99 ff.out:
 100         push    ix
 101         ld      ix,co.fifo              ;
 102
 103 buf.put:
 104         push    hl                      ;
 105         push    bc
 106         push    ix
 107         pop     hl
 108         ld      c,(ix+o.in_idx)         ;
 109         ld      b,0
 110         add     hl,bc
 111         ld      b,a
 112
 113         ld      a,c                     ;
 114         inc     a
 115         and     (ix+o.mask)
 116 bp.wait:
 117         cp      (ix+o.out_idx)          ;
 118         jr      z,bp.wait
 119         ld      (hl),b
 120         ld      (ix+o.in_idx),a
 121
 122         out     (AVRINT6),a
 123         ld      a,b
 124         pop     bc
 125         pop     hl
 126         pop     ix
 127         ret
 128
 129         end
 130