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         maclib z180reg.inc
   9         maclib config.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      de,initab0
  32         dec     c
  33         jr      nz,$+5
  34         ld      de,initab1
  35
  36         ld      c,8                     ;
  37         mlt     bc                      ;
  38         ld      hl,@ctbl+7              ;get baudrate index
  39         add     hl,bc                   ;
  40         ld      a,(hl)
  41         call    as_br_div
  42         ld      b,h
  43         ld      c,l
  44         ld      hl,init_br_off
  45         add     hl,de
  46         ld      (hl),c
  47         inc     hl
  48         ld      (hl),b
  49         ex      de,hl
  50         jp      ioiniml
  51
  52
  53 as_br_div:
  54         push    de
  55         push    bc
  56         and     0fh
  57         add     a,a                     ;get factor
  58         ld      hl,bd150_tab
  59         call    add_hla
  60         ld      c,(hl)
  61         inc     hl
  62         ld      b,(hl)
  63         ld      hl,(f_cpu)
  64         ld      de,(f_cpu+2)
  65         call    div32_r
  66         ld      bc,32*150
  67         call    div32_r
  68         ld      de,2
  69         or      a
  70         sbc     hl,de
  71         pop     bc
  72         pop     de
  73         ret     nc
  74         ld      hl,0
  75         ret
  76
  77 bd150_tab:
  78 ;               factor          index   baudrate        orig. cp/m
  79         dw      19200/150       ; 0     19200           -
  80         dw      28800/150       ; 1     28800           50
  81         dw      38400/150       ; 2     38400           75
  82         dw      57600/150       ; 3     57600           110
  83         dw      11520/15        ; 4     115200          134.5
  84         dw      150/150         ; 5     150
  85         dw      300/150         ; 6     300
  86         dw      600/150         ; 7     600
  87         dw      1200/150        ; 8     1200
  88         dw      1800/150        ; 9     1800
  89         dw      2400/150        ;10     2400
  90         dw      3600/150        ;11     3600
  91         dw      4800/150        ;12     4800
  92         dw      7200/150        ;13     7200
  93         dw      9600/150        ;14     9600
  94         dw      19200/150       ;15     19200
  95
  96
  97
  98
  99 initab0:
 100         db      1,stat0,0               ;Disable rx/tx interrupts
 101                                         ;Enable baud rate generator
 102         db      1,asext0,M_BRGMOD+M_DCD0DIS ; +M_CTS0DIS
 103         db      2,astc0l
 104 init_br_off equ $ - initab0
 105         dw      28
 106         db      1,cntlb0,M_MPBT         ;No MP Mode, X16
 107         db      1,cntla0,M_RE+M_TE+M_MOD2 ;Rx/Tx enable, 8N1
 108         db      0
 109
 110 initab1:
 111         db      1,stat1,0               ;Disable rx/tx ints, disable CTS1
 112         db      1,asext1,M_BRGMOD       ;Enable baud rate generator
 113         db      2,astc1l,low 3, high 3
 114         db      1,cntlb1,M_MPBT         ;No MP Mode, X16
 115         db      1,cntla1,M_RE+M_TE+M_MOD2 ;Rx/Tx enable, 8N1
 116         db      0
 117
 118         end