bankswitched isr example

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@805 4a8a32a2-be11-0410-ad9d-d568d2c75423

diff --git a/device/examples/mcs51/clock/Makefile b/device/examples/mcs51/clock/Makefile
new file mode 100755 (executable)
index 0000000..49ee32b
--- /dev/null
+++ b/device/examples/mcs51/clock/Makefile
@@ -0,0 +1,24 @@
+CC = /home/johan/sdcc/bin/sdcc
+#CFLAGS = -V
+MFLAGS = --model-small --stack-after-data
+#MFLAGS = --model-large --stack-after-data
+LFLAGS = --xram-loc 0x4000 --code-loc 0x0000
+
+all: clock.bin
+
+OBJECTS = clock.rel hwinit.rel
+
+clock.bin: clock.ihx
+       ../hex2bin <clock.ihx >clock.bin
+       cat clock.bin >/dev/par0
+       cu -l /dev/ttyS0 -s 19200 dir
+
+clock.ihx: $(OBJECTS)
+       $(CC) $(MFLAGS) $(LFLAGS) $(OBJECTS)
+
+clean:
+       rm -f core *~ \#* *.asm *.cdb *.rel *.hex *.ihx *.lst *.map \
+               *.rst *.sym *.lnk *.lib *.bin
+
+%.rel: %.c hw.h
+       $(CC) -c $(CFLAGS) $(MFLAGS) $<

diff --git a/device/examples/mcs51/clock/clock.c b/device/examples/mcs51/clock/clock.c
new file mode 100755 (executable)
index 0000000..dabcd55
--- /dev/null
+++ b/device/examples/mcs51/clock/clock.c
@@ -0,0 +1,26 @@
+#include <8051.h>
+#include <stdio.h>
+
+#include "hw.h"
+
+void main(void) {
+  unsigned long ms;
+  unsigned int seconds, oldseconds=ClockTicks()/1000;
+
+  printf ("Example using the core timer to generate seconds.\n");
+
+  while (1) {
+    ms=ClockTicks();
+    seconds=ms/1000;
+    if (oldseconds!=seconds) {
+      oldseconds=seconds;
+      printf ("%02d:%02d.%02d %ld\n", 
+             (int)seconds/3600, (int)(seconds/60)%60, 
+             (int)seconds%60, ms);
+    }
+    if (RI) {
+      putchar(getchar());
+      printf("%ld\n\r", ClockTicks());
+    }
+  }
+}

diff --git a/device/examples/mcs51/clock/hw.h b/device/examples/mcs51/clock/hw.h
new file mode 100755 (executable)
index 0000000..4161a2e
--- /dev/null
+++ b/device/examples/mcs51/clock/hw.h
@@ -0,0 +1,6 @@
+#define OSCILLATOR 11059200
+#define BAUD 19200
+
+void ClockIrqHandler (void) interrupt 1 using 3;
+unsigned long ClockTicks(void);
+

diff --git a/device/examples/mcs51/clock/hwinit.c b/device/examples/mcs51/clock/hwinit.c
new file mode 100755 (executable)
index 0000000..43fe088
--- /dev/null
+++ b/device/examples/mcs51/clock/hwinit.c
@@ -0,0 +1,72 @@
+#include "8051.h"
+
+#include "hw.h"
+
+// timer 0 used for systemclock
+#define TIMER0_RELOAD_VALUE -OSCILLATOR/12/1000 // 0.999348ms for 11.059Mhz
+
+// timer 1 used for baudrate generator
+#define TIMER1_RELOAD_VALUE -(2*OSCILLATOR)/(32*12*BAUD)
+
+static long data milliSeconds;
+
+void ClockIrqHandler (void) interrupt 1 using 3 {
+  TL0 = TIMER0_RELOAD_VALUE&0xff;
+  TH0 = TIMER0_RELOAD_VALUE>>8;
+  milliSeconds++;
+}
+
+// we can't just use milliSeconds
+unsigned long ClockTicks(void) {
+  unsigned long ms;
+  ET0=0;
+  ms=milliSeconds;
+  ET0=1;
+  return ms;
+}
+
+unsigned char _sdcc_external_startup() {
+  // initialize timer0 for system clock
+  TR0=0; // stop timer 0
+  TMOD =(TMOD&0xf0)|0x01; // T0=16bit timer
+  // timeout is xtal/12
+  TL0 = -TIMER0_RELOAD_VALUE&0xff;
+  TH0 = -TIMER0_RELOAD_VALUE>>8;
+  milliSeconds=0; // reset system time
+  TR0=1; // start timer 0
+  ET0=1; // enable timer 0 interrupt
+  
+  // initialize timer1 for baudrate
+  TR1=0; // stop timer 1
+  TMOD = (TMOD&0x0f)|0x20; // T1=8bit autoreload timer
+  // baud = ((2^SMOD)*xtal)/(32*12*(256-TH1))
+  PCON |= 0x80; // SMOD=1: double baudrate
+  TH1=TL1=TIMER1_RELOAD_VALUE;
+  TR1=1; // start timer 1
+
+  // initialize serial port
+  SCON=0x52; // mode 1, ren, txrdy, rxempty
+
+  EA=1; // enable global interrupt
+
+  return 0;
+}
+
+char getchar() {
+  char c;
+  while (!RI)
+    ;
+  RI=0;
+  c=SBUF;
+  return c;
+}
+
+void putchar(char c) {
+  while (!TI)
+    ;
+  TI=0;
+  SBUF=c;
+  if (c=='\n') {
+    putchar('\r');
+  }
+}