PIT Default 
Author Message
 PIT Default

Does anybody know what happens to the PIT during the boot process? I'm
curious to know what state it is in during power-on and then what the
BIOS does to the counters during boot-up.

- Vea



Fri, 27 Aug 1999 03:00:00 GMT  
 PIT Default

Quote:

> Does anybody know what happens to the PIT during the boot process? I'm
> curious to know what state it is in during power-on and then what the
> BIOS does to the counters during boot-up.

> - Vea

Ok, the bios initializes the timers during boot-up, by programming the
default values into the registers like 18h for the refresh timer etc...
and FFFFh for the bios timer tick.

greetings,

paul.

--
/********************************************
                Paul F. Vollebregt  
http:           www.worldonline.nl/~vollebre

/********************************************



Sat, 28 Aug 1999 03:00:00 GMT  
 PIT Default

In case anybody wants to know, here is the answer to my question. It came
from http://developer.intel.com/design/periphrl/overview/7178.HTM

Q7. What is the default state of the 8254 upon power up or reset?
A7. The device does not have a dedicated reset pin. At power up, the
default condition of the 8254 is undefined. The mode, count value,
and state of the OUT pins are undefined or random. Each counter must be
initialized via software before it can be used.

- Vea



Sat, 28 Aug 1999 03:00:00 GMT  
 PIT Default

Quote:

> Does anybody know what happens to the PIT during the boot process? I'm
> curious to know what state it is in during power-on and then what the
> BIOS does to the counters during boot-up.

I'd guess that the PIT is reset during power-up which for most devices
is disabled, i.e. don't generate interrupts. It'll be enabled somewhere
down the way, I'd guess in the BIOS.

Regards, Rob.



Wed, 01 Sep 1999 03:00:00 GMT  
 
 [ 4 post ] 

 Relevant Pages 

1. PIT Default

2. dict.get(key, default): conditional default evaluation

3. *default-pathname-defaults* ?

4. Pit Your Wits Against This One...

5. tutorials 'bout PIC and PIT

6. Stopping a PIT

7. PIT Start / Stop

8. HOW CAN I IMPLEMENT SOFTWARE DELAYS USING ONE OF THE 6 MODES OF THE PIT

9. 8253 Programmable Interval Timer (PIT)??

10. PIC and PIT programming

11. PIT

12. Stopping a PIT

 

 
Powered by phpBB® Forum Software