memory.h \
psw.c psw.h \
sfr.c sfr.h \
+ timers.c timers.h \
common.h \
reg8051.h
#include "cpu8051.h"
#include "memory.h"
#include "psw.h"
+#include "timers.h"
#include "disasm.h"
#include "options.h"
#include "instructions_8051.h"
}
}
-static void
-process_timer(uint8_t tl, uint8_t th, uint8_t tf_mask, uint8_t TR, uint8_t mode,
- uint8_t GATE, uint32_t TimerCounter)
-{
- unsigned int tmp;
- unsigned int prescaler;
-
- switch (mode) {
- case 0:
- /* Mode 0, 8-bit timer "TH" with "TL" as 5-bit prescaler. */
- prescaler = cpu8051_ReadD(tl);
- prescaler++;
- prescaler &= 0x1F; /* We keep only 5 bits */
- cpu8051_WriteD(tl, prescaler);
-
- if (prescaler == 0) {
- /* If overflow, increment TH */
- tmp = cpu8051_ReadD(th);
- tmp++;
- tmp &= 0xFF; /* We keep only 8 bits */
-
- if (tmp == 0) /* If overflow set TF */
- cpu8051_WriteD(_TCON_, cpu8051_ReadD(_TCON_) | tf_mask);
-
- cpu8051_WriteD(th, tmp);
- }
- break;
- case 1:
- /* Mode 1, 16-bits counter */
- tmp = cpu8051_ReadD(th) * 0x100 + cpu8051_ReadD(tl);
- tmp++;
- tmp &= 0xFFFF; /* We keep only 16 bits */
- if (tmp == 0) /* If overflow set TF0 */
- cpu8051_WriteD(_TCON_, cpu8051_ReadD(_TCON_) | tf_mask);
- cpu8051_WriteD(th, (tmp / 0x100));
- cpu8051_WriteD(tl, (tmp & 0xFF));
- break;
- case 2:
- /* Mode 2, 8-bits counter with Auto-Reload */
- tmp = cpu8051_ReadD(tl);
- tmp++;
- tmp &= 0xFF;
- if (tmp == 0) {
- /* If overflow -> reload and set TF0 */
- cpu8051_WriteD(_TCON_, cpu8051_ReadD(_TCON_) | tf_mask);
- cpu8051_WriteD(tl, cpu8051_ReadD(th));
- } else
- cpu8051_WriteD(tl, tmp);
- break;
- case 3:
- /* Mode 3 : inactive mode for timer 1 */
- if (tl == _TL0_) {
- /* TL0 and TH0 are 2 independents 8-bits timers. */
- if (TR && !GATE && !TimerCounter) {
- tmp = cpu8051_ReadD(tl);
- tmp++;
- tmp &= 0xFF;
- if (tmp == 0) /* If TL0 overflow set TF0 */
- cpu8051_WriteD(_TCON_,
- cpu8051_ReadD(_TCON_) |
- tf_mask);
- cpu8051_WriteD(tl, tmp);
- } /* TH0 utilise TR1 et TF1. */
- TR = cpu8051_ReadD(_TCON_) & 0x40;
- if (TR) {
- tmp = cpu8051_ReadD(th);
- tmp++;
- tmp &= 0xFF;
- if (tmp == 0) /* If TH0 overflow set TF1 */
- cpu8051_WriteD(_TCON_,
- cpu8051_ReadD(_TCON_) |
- 0x80);
- cpu8051_WriteD(_TH0_, tmp);
- }
- }
- break;
- }
-}
-
-/* Run timers */
-static void
-cpu8051_DoTimers(void)
-{
- unsigned int TR;
- unsigned int MODE;
- unsigned int GATE;
- unsigned int TimerCounter;
-
- /* Timer 0 */
- TR = cpu8051_ReadD(_TCON_) & 0x10;
- MODE = cpu8051_ReadD(_TMOD_) & 0x03;
- GATE = cpu8051_ReadD(_TMOD_) & 0x08;
- TimerCounter = cpu8051_ReadD(_TMOD_) & 0x04;
-
- if ((TR && !GATE && !TimerCounter) || (MODE == 3))
- process_timer(_TL0_, _TH0_, 0x20, TR, MODE, GATE, TimerCounter);
-
- /* Timer 1 */
- TR = cpu8051_ReadD(_TCON_) & 0x40;
- MODE = (cpu8051_ReadD(_TMOD_) & 0x30) >> 4 ;
- GATE = cpu8051_ReadD(_TMOD_) & 0x80;
- TimerCounter = cpu8051_ReadD(_TMOD_) & 0x40;
-
- if (TR && !GATE && !TimerCounter)
- process_timer(_TL1_, _TH1_, 0x80, TR, MODE, GATE, TimerCounter);
-}
-
/* Execute at address cpu8051.pc from PGMMem */
void
cpu8051_Exec(void)
for (i = 0; i < insttiming; i++) {
cpu8051_CheckInterrupts();
- cpu8051_DoTimers();
+ timers_check();
cpu8051.clock++;
}
}
--- /dev/null
+/*
+ * timers.c
+ *
+ * Copyright (C) 1999 Jonathan St-André
+ * Copyright (C) 1999 Hugo Villeneuve <hugo@hugovil.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include "config.h"
+
+#include "common.h"
+#include "reg8051.h"
+#include "cpu8051.h"
+#include "memory.h"
+#include "psw.h"
+#include "options.h"
+#include "instructions_8051.h"
+
+extern struct options_t options;
+
+static void
+timer_increment_check_overflow(uint8_t counter_address, uint8_t tf_mask)
+{
+ unsigned int tmp;
+
+ tmp = cpu8051_ReadD(counter_address);
+ tmp++;
+ tmp &= 0xFF;
+ if (tmp == 0) {
+ /* If overflow set TFx */
+ cpu8051_WriteD(_TCON_, cpu8051_ReadD(_TCON_) | tf_mask);
+ }
+
+ cpu8051_WriteD(counter_address, tmp); /* Save new value. */
+}
+
+static void
+timer_with_prescaler(uint8_t tl, uint8_t th, uint8_t tf_mask, int prescaler_width)
+{
+ unsigned int prescaler;
+
+ prescaler = cpu8051_ReadD(tl);
+ prescaler++;
+
+ prescaler &= (1 << prescaler_width) - 1; /* Keep only required bits */
+ cpu8051_WriteD(tl, prescaler);
+
+ if (prescaler == 0)
+ timer_increment_check_overflow(th, tf_mask);
+}
+
+static void
+process_timer(uint8_t tl, uint8_t th, uint8_t tf_mask, uint8_t TR, uint8_t mode,
+ uint8_t GATE, uint32_t TimerCounter)
+{
+ unsigned int tmp;
+
+ switch (mode) {
+ case 0:
+ /* Mode 0, 8-bit timer "TH" with "TL" as 5-bit prescaler. */
+ timer_with_prescaler(tl, th, tf_mask, 5);
+ break;
+ case 1:
+ /* Mode 1, 16-bits counter */
+ timer_with_prescaler(tl, th, tf_mask, 8);
+ break;
+ case 2:
+ /* Mode 2, 8-bits counter with Auto-Reload */
+ tmp = cpu8051_ReadD(tl);
+ tmp++;
+ tmp &= 0xFF;
+ if (tmp == 0) {
+ /* If overflow -> reload and set TF0 */
+ cpu8051_WriteD(_TCON_, cpu8051_ReadD(_TCON_) | tf_mask);
+ cpu8051_WriteD(tl, cpu8051_ReadD(th));
+ } else
+ cpu8051_WriteD(tl, tmp);
+ break;
+ case 3:
+ /*
+ * Mode 3:
+ * inactive mode for timer 1
+ * 2 independents 8-bits timers for timer 0.
+ */
+
+ if (tl == _TL1_)
+ break;
+
+ if (TR && !GATE && !TimerCounter)
+ timer_increment_check_overflow(tl, tf_mask);
+
+ /* TH0 uses TR1 et TF1. */
+ TR = cpu8051_ReadD(_TCON_) & 0x40;
+
+ if (TR)
+ timer_increment_check_overflow(th, 0x80);
+
+ break;
+ }
+}
+
+/* Run timers */
+void
+timers_check(void)
+{
+ unsigned int TR;
+ unsigned int MODE;
+ unsigned int GATE;
+ unsigned int TimerCounter;
+
+ /* Timer 0 */
+ TR = cpu8051_ReadD(_TCON_) & 0x10;
+ MODE = cpu8051_ReadD(_TMOD_) & 0x03;
+ GATE = cpu8051_ReadD(_TMOD_) & 0x08;
+ TimerCounter = cpu8051_ReadD(_TMOD_) & 0x04;
+
+ if ((TR && !GATE && !TimerCounter) || (MODE == 3))
+ process_timer(_TL0_, _TH0_, 0x20, TR, MODE, GATE, TimerCounter);
+
+ /* Timer 1 */
+ TR = cpu8051_ReadD(_TCON_) & 0x40;
+ MODE = (cpu8051_ReadD(_TMOD_) & 0x30) >> 4 ;
+ GATE = cpu8051_ReadD(_TMOD_) & 0x80;
+ TimerCounter = cpu8051_ReadD(_TMOD_) & 0x40;
+
+ if (TR && !GATE && !TimerCounter)
+ process_timer(_TL1_, _TH1_, 0x80, TR, MODE, GATE, TimerCounter);
+}
--- /dev/null
+/*
+ * timers.h
+ *
+ * Copyright (C) 2013 Hugo Villeneuve <hugo@hugovil.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef TIMERS_H
+#define TIMERS_H 1
+
+#include <stdint.h>
+
+int
+timers_check(void);
+
+#endif /* TIMERS_H */
projects / emu8051.git / commitdiff