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About key's interrupt

cdvehicle
Associate II
Posted on April 23, 2005 at 10:10

About key's interrupt

19 REPLIES 19
cdvehicle
Associate II
Posted on April 20, 2005 at 16:12

1\when BIOS booting I press the key, the IRQ1's level from LOW to HIGH , bus it can notback to LOW, I thnk the BIOS can not read this key code. why? Does the IRQMUX is not right?

2\And Demo borad display the screen message ''Boot....'' is very slowly ., why?

(And IRQ6 /IRQ12 is LOW, others is HIGH)

marios
Associate II
Posted on April 20, 2005 at 20:44

At what post code are you now?

If the IRQ1 goes high it means that the keyboard controller has sent an IRQ to the CPU, so the KB controller seems to work. If it does not go back to low, it means that the CPU was unable to service the interrupt and tell the KB controller to lower the IRQ.

At power-up, do you see the keyboard lights going ON then OFF?

IRQ6 and 12 at low mean that the floppy and the mouse interrupts are enabled.

cdvehicle
Associate II
Posted on April 21, 2005 at 03:16

The IRQ1 is toggled when power-on. The BIOS goes to boot disk

and send to screen ''R- reboot / S - setup / ESC - Debug'' (hi ram/low ram passed) but running speed is very slowly. I test the

IRQ1 it was low, but when I press the key the IRQ1 goes to hi.

I make a CPLD which function same as 74LS153(IRQMUX/DREQ_MUX/DACK_ENC/DACK). Is it IRQMUX or DREQ or DACK wrong?

Another question : the IDE signal SA_DD0..SA_DD15 is about 2V when BIOS send this message ''R- reboot / S - setup / ESC - Debug'', is it right? (When Power-on, SA_DD[0..15] can goes to 3.3V.)

At last the post code is 0x00

[ This message was edited by: vehicle007 on 21-04-2005 06:53 ]

marios
Associate II
Posted on April 21, 2005 at 13:39

At that point only you can test if the CPLD does a good job at working like the 153.

When the BIOS executes the memory test, does it accelerate the test when you press ? If not, you have to pay atention to the keyboard interface. Possibly your IRQ mapper.

The last post code of 00 means that it has given the control, to the operating system, if it was able to find one. If there are boot devices specified in the BIOS and that they are not present, you may see the post code 90 appearing for quite a while.

marios
Associate II
Posted on April 21, 2005 at 13:48

2 volts usually means that something floats, or that all the devices on the bus are in input mode. It might happen if there is an ISA bus-master DMA transfer that is occuring, otherwise the ISA addresses are always driven by the CPU. Check your circuitry associated to the ISA bus-master. My feeling.

cdvehicle
Associate II
Posted on April 22, 2005 at 03:23

When the BIOS executes the memory test, does it accelerate the test when you press ? If not, you have to pay atention to the keyboard interface. Possibly your IRQ mapper.

---------------

I check it , it is right, because the IRQ1 goes to HIGH when I press the key. And the BIOS running slowly . Whether signal of DMA or IRQ have the influence or not?

when power-on the keyboard's 'numlock'/capslocks'/'scrolllock'

led flash once and turn off, (the IRQ1 goes to HIGH then goes to LOW )

follows is my cpld equations

IRQMUX[0:3]

assign IRQMUX=

( ISACLK==0 && ISACLK2==0 )?{ 1'b0, IRQ4, IRQ8, IRQ12 }:

( ISACLK==0 && ISACLK2==1 )?{ IRQ1, IRQ5, IRQ9, 1'b0 }:

( ISACLK==1 && ISACLK2==0 )?{ 1'b0, IRQ6, IRQ10, IRQ14 }://1'b0, IRQ6 10, 14

( ISACLK==1 && ISACLK2==1 )?{ IRQ3, IRQ7, IRQ11, IRQ15 }://3,7,11,15

4'h0;

[ This message was edited by: vehicle007 on 22-04-2005 09:37 ]

[ This message was edited by: vehicle007 on 22-04-2005 11:41 ]

twitwity
Associate II
Posted on April 22, 2005 at 08:15

once the BIOS codes shows 00 it has gone through BIOS initialization, and you saw the message, then it went up to the point of OS boot. (congrat!)

first of all did you probe IDE signals and sure is it working? (signals on data bits should togle..) and if you press enter repetedly, the the boot message repeats itself on the screen? )

the IRQs discussed are only the IRQs attatched to SIO. - ISA bus. the IRQ line assigned to IDE actually travels inside the CPU. probe the connector side of HDD.. if you test your key inputs and message repeats. you can go on to next phase. the boot device.

the boot message seems to be that of GeneraSoftware. and press ctrl-c when it enters BIOS screen and check the boot device setting in menu.

if things are not so widely different from VEGA's case, (and of course, i'm so sure it is not.) the DDx signals are directly from the CPU and it is working at 3.3v level. when it is in working state. it shows 2.3~ volt level. the IDE interface is TTL Level and the low level is thought to be more important. 2.5v will work quite stably.

check the key response and DDx signals on IDE. that is the turning point of yours..

(attatched is technical part scratched from ATA3 definition DOC. for reference. but usually. the IDE HDD should boot without pain. please. refer to it )

good luck!.

(ah sorry. probe IDE activity. - DDx might be shared with ISA bus signals.. see if signal goes out from CPU to IDE HDD)

[ This message was edited by: Twitwity on 22-04-2005 12:22 ]

twitwity
Associate II
Posted on April 22, 2005 at 08:31

HDL codes looks alright.

what device are you using?

look. the careless signal probing while chip is running can make signal electrically dirty and that can get the system crashed..

[ This message was edited by: Twitwity on 22-04-2005 12:16 ]

cdvehicle
Associate II
Posted on April 22, 2005 at 09:10

I use a DOC2000, it can be boot DOS. (IDE harddisk fail!).

when BIOS poweron, BIOS can not test the key, after boot DOS,

could the PS2 keyborad be respond? I add MAX213 for serial communcation, but the IRQ4 is HIGH, can not goes to LOW.

so I think, some error at another postion.

important, the systemborad boot the operat-system very slowly.