cbios/asci-cmn.180

   1
   2         public  as_init
   3
   4         extrn   ioiniml
   5         extrn   f_cpu,add_hla,div32_r
   6         extrn   @ctbl
   7
   8         include config.inc
   9         include z180reg.inc
  10
  11
  12 ;--------------------------------------------------------------
  13 ; TC = (f PHI /(2*baudrate*Clock_mode)) - 2
  14 ;
  15 ; Clock_mode == 16
  16 ;       TC = (f PHI / (32 * baudrate)) - 2
  17 ;
  18 ; br150 = baudrate/150
  19 ;       TC = (f PHI / (32 * 150 * br150)) - 2
  20 ;       TC = (f PHI / (32 * 150 * br150)) - 2
  21
  22
  23 ;--------------------------------------------------------------
  24 ; Init Serial I/O for console input and output (ASCI1)
  25 ;
  26 ; b: device number (0..15)
  27 ; c: asci channel number (0/1)
  28
  29         dseg
  30 as_init:
  31         ld      hl,initab0
  32         dec     c
  33         jr      nz,$+5
  34         ld      hl,initab1
  35
  36         push    hl
  37         ld      c,8                     ;
  38         mlt     bc                      ;
  39         ld      hl,@ctbl+7              ;get baudrate index
  40         add     hl,bc                   ;
  41         ld      a,(hl)
  42         and     0fh
  43         add     a,a                     ;get factor
  44         ld      hl,bd150_tab
  45         call    add_hla
  46         ld      c,(hl)
  47         inc     hl
  48         ld      b,(hl)
  49         ld      hl,(f_cpu)
  50         ld      de,(f_cpu+2)
  51         call    div32_r
  52         ld      bc,32*150
  53         call    div32_r
  54         ld      de,2
  55         or      a
  56         sbc     hl,de
  57         jr      nc,as_ini_1
  58         ld      hl,0
  59 as_ini_1:
  60         ld      b,h
  61         ld      c,l
  62         pop     de
  63         ld      hl,init_br_off
  64         add     hl,de
  65         ld      (hl),c
  66         inc     hl
  67         ld      (hl),b
  68         ex      de,hl
  69         jp      ioiniml
  70
  71
  72 bd150_tab:
  73 ;               factor          index   baudrate        orig. cp/m
  74         dw      19200/150       ; 0     19200           -
  75         dw      28800/150       ; 1     28800           50
  76         dw      38400/150       ; 2     38400           75
  77         dw      57600/150       ; 3     57600           110
  78         dw      11520/15        ; 4     115200          134.5
  79         dw      150/150         ; 5     150
  80         dw      300/150         ; 6     300
  81         dw      600/150         ; 7     600
  82         dw      1200/150        ; 8     1200
  83         dw      1800/150        ; 9     1800
  84         dw      2400/150        ;10     2400
  85         dw      3600/150        ;11     3600
  86         dw      4800/150        ;12     4800
  87         dw      7200/150        ;13     7200
  88         dw      9600/150        ;14     9600
  89         dw      19200/150       ;15     19200
  90
  91
  92
  93
  94 initab0:
  95         db      1,stat0,0               ;Disable rx/tx interrupts
  96                                         ;Enable baud rate generator
  97         db      1,asext0,M_BRGMOD+M_DCD0DIS ; +M_CTS0DIS
  98         db      2,astc0l
  99 init_br_off equ $ - initab0
 100         dw      28
 101         db      1,cntlb0,M_MPBT         ;No MP Mode, X16
 102         db      1,cntla0,M_RE+M_TE+M_MOD2 ;Rx/Tx enable, 8N1
 103         db      0
 104
 105 initab1:
 106         db      1,stat1,0               ;Disable rx/tx ints, disable CTS1
 107         db      1,asext1,M_BRGMOD       ;Enable baud rate generator
 108         db      2,astc1l,low 3, high 3
 109         db      1,cntlb1,M_MPBT         ;No MP Mode, X16
 110         db      1,cntla1,M_RE+M_TE+M_MOD2 ;Rx/Tx enable, 8N1
 111         db      0
 112
 113         end