sdcc-extra/historygraphs/whetstone-z80/portme.c

   1 #include <stdio.h>
   2 #include <stdint.h>
   3
   4 __sfr __at 0x00 Exec_port;
   5 __sfr __at 0x01 StorOpc_port;
   6
   7 volatile unsigned long ticks;
   8
   9 void init (void)
  10 {
  11         // Setup tick interrupt.
  12         StorOpc_port = 0x0f; // Set tick opcode
  13         Exec_port = 10; // Once every 10 ms.
  14
  15         StorOpc_port = 0x0e; // Set interrupt opcode
  16         Exec_port = 0x02; // Tick interrupt only.
  17
  18 __asm
  19         im      1
  20         ei
  21 __endasm;
  22 }
  23
  24 void tick (void)
  25 {
  26         ticks++;
  27 }
  28
  29 unsigned long clock(void)
  30 {
  31         long ret;
  32         do
  33                 ret = ticks;
  34         while (ret != ticks);
  35         return(ret * 10);
  36 }
  37
  38 #if defined(__SDCC) && __SDCC_REVISION < 9624 // Old SDCC weirdness
  39 void putchar (char c)
  40 {
  41 __asm
  42         di
  43 __endasm;
  44         StorOpc_port = 0x1;
  45         Exec_port = c;
  46 __asm
  47         ei
  48 __endasm;
  49 }
  50 #else // Standard C
  51 int putchar (int c)
  52 {
  53 __asm
  54         di
  55 __endasm;
  56         StorOpc_port = 0x1;
  57         Exec_port = c;
  58 __asm
  59         ei
  60 __endasm;
  61         return(c);
  62 }
  63 #endif
  64