/* Execute some instructions until we use up cycles clock cycles */
int m68k_execute(m68ki_cpu_core *m68k, unsigned int cycles)
{
m68k->initial_cycles = cycles;
/* eat up any reset cycles */
if (m68k->reset_cycles) {
int rc = m68k->reset_cycles;
m68k->reset_cycles = 0;
cycles -= rc;
if (cycles <= 0) return rc;
}
/* Set our pool of clock cycles available */
m68k->remaining_cycles = cycles;
/* See if interrupts came in */
m68ki_check_interrupts(m68k);
/* Make sure we're not stopped */
if(!m68k->stopped)
{
/* Return point if we had an address error */
m68ki_set_address_error_trap(m68k); /* auto-disable (see m68kcpu.h) */
/* Main loop. Keep going until we run out of clock cycles */
do
{
/* Set tracing accodring to T1. (T0 is done inside instruction) */
m68ki_trace_t1(); /* auto-disable (see m68kcpu.h) */
/* Record previous program counter */
REG_PPC = REG_PC;
/* Read an instruction and call its handler */
m68k->ir = m68ki_read_imm_16(m68k);
m68ki_instruction_jump_table[m68k->ir](m68k);
m68k->remaining_cycles -= m68k->cyc_instruction[m68k->ir];
/* Trace m68k_exception, if necessary */
m68ki_exception_if_trace(); /* auto-disable (see m68kcpu.h) */
} while (m68k->remaining_cycles > 0);
/* set previous PC to current PC for the next entry into the loop */
REG_PPC = REG_PC;
}
else if (m68k->remaining_cycles > 0)
m68k->remaining_cycles = 0;
/* return how many clocks we used */
return m68k->initial_cycles - m68k->remaining_cycles;
}
/* ASG: rewrote so that the int_level is a mask of the IPL0/IPL1/IPL2 bits */
void m68k_set_irq(unsigned int intLevel)
{
#if 0
uint old_level = CPU_INT_LEVEL;
CPU_INT_LEVEL = int_level << 8;
/* A transition from < 7 to 7 always interrupts (NMI) */
/* Note: Level 7 can also level trigger like a normal IRQ */
if(old_level != 0x0700 && CPU_INT_LEVEL == 0x0700)
m68ki_exception_interrupt(7); /* Edge triggered level 7 (NMI) */
else
m68ki_check_interrupts(); /* Level triggered (IRQ) */
#else
int oldLevel = regs.intLevel;
regs.intLevel = intLevel;
// A transition from < 7 to 7 always interrupts (NMI)
// Note: Level 7 can also level trigger like a normal IRQ
if (oldLevel != 0x07 && regs.intLevel == 0x07)
m68ki_exception_interrupt(7); // Edge triggered level 7 (NMI)
else
m68ki_check_interrupts(); // Level triggered (IRQ)
#endif
}
/* ASG: rewrote so that the int_level is a mask of the IPL0/IPL1/IPL2 bits */
void m68k_set_irq2(unsigned int intLevel)
{
// pthread_mutex_lock(&executionLock);
// printf("m68k_set_irq: Could not get the lock!!!\n");
int oldLevel = regs.intLevel;
regs.intLevel = intLevel;
// A transition from < 7 to 7 always interrupts (NMI)
// Note: Level 7 can also level trigger like a normal IRQ
if (oldLevel != 0x07 && regs.intLevel == 0x07)
m68ki_exception_interrupt(7); // Edge triggered level 7 (NMI)
else
m68ki_check_interrupts(); // Level triggered (IRQ)
// pthread_mutex_unlock(&executionLock);
}
