Retro/pcem
Watch
1
0
Fork
You've already forked pcem
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Implement CPU clock control on SCAT. Patch from Greatpsycho.

Browse source
This commit is contained in:
SarahW 2020-11-16 17:59:57 +00:00
commit d5dbe302b5
3 changed files with 24 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

17
src/cpu.c
View file

@ -212,6 +212,7 @@ void cpu_set()
cpu_nonturbo_speed = cpu_s->rspeed;
else
cpu_nonturbo_speed = 8000000;
cpu_turbo = 1;
cpu_update_waitstates();
@ -2181,9 +2182,25 @@ void cpu_set_turbo(int turbo)
}
}
int cpu_get_turbo()
{
return cpu_turbo;
}
int cpu_get_speed()
{
if (cpu_turbo)
return cpu_turbo_speed;
return cpu_nonturbo_speed;
}
void cpu_set_nonturbo_divider(int divider)
{
if (divider < 2)
cpu_set_turbo(1);
else
{
cpu_nonturbo_speed = cpu_turbo_speed / divider;
cpu_set_turbo(0);
}
}

3
src/cpu.h
View file

@ -196,10 +196,13 @@ extern uint64_t xt_cpu_multi;
extern int isa_cycles;
#define ISA_CYCLES(x) (x * isa_cycles)
#define CPU_CLOCK_DIVIDER_MAX 16384
void cpu_update_waitstates();
void cpu_set();
void cpu_set_edx();
void cpu_set_turbo(int turbo);
int cpu_get_turbo();
void cpu_set_nonturbo_divider(int divider);
int cpu_get_speed();
extern int has_vlb;

6
src/scat.c
View file

@ -1046,8 +1046,7 @@ void scat_write(uint16_t port, uint8_t val, void *priv)
scat_reg_valid = 1;
break;
case SCAT_POWER_MANAGEMENT:
// TODO - Only use AUX parity disable bit for this version. Other bits should be implemented later.
val &= (scat_regs[SCAT_VERSION] & 0xF0) == 0 ? 0x40 : 0x60;
cpu_set_nonturbo_divider((val & 0xc) > 0 ? 1 << ((val & 0xc) >> 2) : 0);
scat_reg_valid = 1;
break;
case SCAT_DRAM_CONFIGURATION:
@ -1220,6 +1219,9 @@ uint8_t scat_read(uint16_t port, void *priv)
case SCAT_MISCELLANEOUS_STATUS:
val = (scat_regs[scat_index] & 0x3f) | (~nmi_mask & 0x80) | ((mem_a20_key & 2) << 5);
break;
case SCAT_POWER_MANAGEMENT:
val = (scat_regs[scat_index] & (cpu_get_turbo() ? 0xF3 : 0xFF));
break;
case SCAT_DRAM_CONFIGURATION:
if ((scat_regs[SCAT_VERSION] & 0xF0) == 0) val = (scat_regs[scat_index] & 0x8f) | (cpu_waitstates == 1 ? 0 : 0x10);
else val = scat_regs[scat_index];