iwjpictest/syncwritehex.asm

   1 ;======================================================================
   2 ;
   3 ; these routines all use serial_write_char which writes
   4 ; bytes to the serial port synchronously
   5
   6         radix           dec
   7         include         ../iwjpictest/insn-aliases.inc
   8
   9         udata_acs
  10 serial_hex_temp res 1
  11
  12  code
  13 ;----------------------------------------------------------------------
  14
  15 ;----------------------------------------
  16 serial_write_hex
  17 ;       transmits W in hex through serial port, using serial_write_char
  18 ;                       Before          After
  19 ; W                     value           undefined
  20 ; serial_hex_temp       undefined       undefined
  21         mov_wf          serial_hex_temp
  22         rcall           serial_write_hex_1digit_for_both
  23         rcall           serial_write_hex_1digit_for_both
  24         return
  25
  26 ;--------------------
  27 serial_write_hex_1digit_for_both
  28 ;       transmits top nybble of serial_hex_temp in hex
  29 ;       through serial port, as above, and swaps nybbles
  30 ;               Before          After
  31 ; W                     any             undefined
  32 ; serial_hex_temp       BBBBaaaa        aaaaBBBB        (BBBB was sent)
  33         swap_f  serial_hex_temp
  34         mov_fw  serial_hex_temp
  35 ;...
  36 ;--------------------
  37 serial_write_hex_digit
  38 ;       transmits bottom nybble of W in hex
  39 ; W             ????VVVV        undefined
  40         and_lw  0x0f
  41         sub_lw  10
  42         sub_lw  0
  43         bra_n   serial_write_hex_digit_ifnot_ge10
  44         add_lw  'a'-('0'+10)
  45 serial_write_hex_digit_ifnot_ge10
  46         add_lw  '0'+10
  47         bra     serial_write_char
  48
  49 ;======================================================================
  50  include ../iwjpictest/syncwrite.inc
  51  end