Squidge
Certified Guru
I don't see whats wrong with the Linux function gettimeofday() which can give you accuracy down to 1 μsec / 1 Mhz, but also gives seconds since epoch if you want something a bit slower.
Highspeed Timer(Counter)
- Thread starter Pickle
- Start date
Pickle
Mega GP Mania
Squidge said:
I did have that before trying the rtc in libcastor seemed to work too. Although I think SDL's time functions are based off it, so if SDL timing is off gettimeofdaymay be off too. Like the example exophase gave, maybe something isnt right in the kernel.
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notaz
Certified Guru
RTC and timer are different things. RTC remembers wall clock when the unit is off (seems to work fine), timer does high precision stuff (also works fine). The problem is with buggy code in some system calls that causes accuracy drop to ~8ms.
See post #6 of this thread.Squidge said:
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Pickle
Mega GP Mania
Notaz, you said you used one of the five other hw timers with success can you please give some specifics on how you used it?
Exophase
Nothing good will ever come of Exophase.
Hey Pickle. Do you have the Pollux manual? I could send it to you if you don't. It'll explain how to use the timers.
Squidge
Certified Guru
Ah right, I see. Sounds like yet another GPH fubar.notaz said:
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Pickle
Mega GP Mania
Exophase said:
I dont have the manual.
Seems you cant receive any more PM's Pop in on IRC if have some time.
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Exophase
Nothing good will ever come of Exophase.
That's odd, I should have room there. I cleared some more, so you might want to try again. I'm not really on IRC very much now and you always seemed to miss me before so that might not work. If I don't hear from you I'll PM you my e-mail address.
Pickle
Mega GP Mania
Exophase said:
dont worry about it ;-)
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satacoy
Still Fresh
- Joined
- May 1, 2006
- Messages
- 81
Pickle said:
Did anyone ever figure out how to get a reliable clock down to the millisecond (or better) range? I'd like to calculate how many milliseconds have passed since the last frame, the libcastor lc_gettime() function doesn't appear to be nearly accurate enough.
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Pickle
Mega GP Mania
satacoy said:
yeah dont use lc_gettime, like it was said that is for RTC timing.
Im looking into using some timer hw directly and add it to libcastor.
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Pickle
Mega GP Mania
crow_riot said:Pickle said:
is there any progression/update on this ? ...
if not, may someone send me that pollux manual?
I got as far as to read the active timer, but setting the others hasnt worked. Ive put on the side for now, ive lost interest for now
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pseudonym404
Still Fresh
- Joined
- Dec 24, 2008
- Messages
- 32
crow_riot said:
I'd love a copy of any documentation going too if it's OK to distribute it. OLED controller and NAND datasheets were easy enough to find, but I can't find any SoC docs.
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pseudonym404 said:I'd love a copy of any documentation going too if it's OK to distribute it. OLED controller and NAND datasheets were easy enough to find, but I can't find any SoC docs.
didn't get one either. i was desperately searching for a manual, but no chance to find. i also asked a friend of mine in china to check out if he can reach mesdigital.com - but not even from there
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Orkie
Super Duper Mega GP Mania
MES won't give you one anyway. They do hand them out in exchange for large sums of money, but they even only do that under NDA.
notaz
Certified Guru
here's the code that I use in PicoDrive:
This is accurate 32bit microsecond timer, using one of (currently) free SoC timers. Since it's 32bit it will wrap every 4295 seconds, so don't cause deadlocks for someone playing for more than a hour and a bit
Also be nice and don't forget to call ptimer_cleanup() to free the timer on exit.
oh BTW 'memregl' is standard
Code:
#define TIMER_BASE3 0x1980
#define TIMER_REG(x) memregl[(TIMER_BASE3 + x) >> 2]
void ptimer_init(void)
{
TIMER_REG(0x44) = 0x922;
TIMER_REG(0x40) = 0x0c;
TIMER_REG(0x08) = 0x6b;
}
unsigned int ptimer_get_ticks_us(void)
{
TIMER_REG(0x08) = 0x4b; /* run timer, latch value */
return TIMER_REG(0);
}
void ptimer_cleanup(void)
{
TIMER_REG(0x40) = 0x0c;
TIMER_REG(0x08) = 0x23;
TIMER_REG(0x00) = 0;
TIMER_REG(0x40) = 0;
TIMER_REG(0x44) = 0;
}This is accurate 32bit microsecond timer, using one of (currently) free SoC timers. Since it's 32bit it will wrap every 4295 seconds, so don't cause deadlocks for someone playing for more than a hour and a bit
Also be nice and don't forget to call ptimer_cleanup() to free the timer on exit.
oh BTW 'memregl' is standard
Code:
volatile unsigned int *memregl;
int memdev = open("/dev/mem", O_RDWR);
memregl = mmap(0, 0x20000, PROT_READ|PROT_WRITE, MAP_SHARED, memdev, 0xc0000000);