STPC Elite - GPIO configuration

[abendor]

Posted on May 12, 2005 at 11:34

STPC Elite - GPIO configuration

[abendor]

Posted on June 24, 2003 at 05:50

Hello,

I am using the STPC Elite. I would like to configure the registers controlling the GPIO. However, the values that I set in the control registers are never set, and the default value always stays there.

For example:

When I set a value to register 0x320 (Port Direction Control), it's value always stays 0xFF.

How do I enable and control the GPIO?

Thanks!

[stephen239955_st]

Posted on June 24, 2003 at 06:33

The GPIOs are set using the miscelaneous register on the PCI. That is register 40h.

Before you can use the GPIOs, you need to enable them via this register.

[abendor]

Posted on June 24, 2003 at 08:18

To access register 40h, what values should I set to Register 0xCf8 -

Enable - 1???

Bus number - ???

Device number - ???

Function number - ???

Register number - 40h

Thanks!

[abendor]

Posted on June 25, 2003 at 11:08

When accessing the PCI configuration registers - register 0xCF8 has 6 bits for the register number (bites 2...7). It means that the highest register number that can be accessed is 0x3F.

How can I access the SOUTH BRIDGE MISCELLANEOUS REGISTER which has offset of 0x40?

Thanks!

[thierry239955_st]

Posted on June 25, 2003 at 11:41

The register number is 8 bits large! The contend of the 0xcf8 register is:

1BBBBBBB BBBBBBBB DDDDDFFF RRRRRRRR

bit 31----------bit 0

B=Bus, 15 bits, 16-30

D=Device, 5 bits, 11-15

F=Function, 3 bits, 8-10

R=Register, 8 bits, 0-7

(bit 31 is always to 1)

Farfalla

[ This message was edited by: Farfalla on 25-06-2003 15:13 ]

[gordon]

Posted on February 06, 2004 at 17:36

So that would be 0x80006040, resulting in something like this(?):

Code:

<BR>mov ax, 80006040h ;SB_Misc0 <BR>mov dx, 0cf8h <BR>out dx,ax <BR> <BR>mov ax 2 ; enable gpio <BR>mov dx, 0cfch <BR>out dx,ax <BR>

Then we are free to do I/O to 320..327 for the lower byte of gpio, no?

[ This message was edited by: Gordon on 06-02-2004 22:07 ]

[gordon]

Posted on February 23, 2004 at 21:03

Turns out, my suggestion wasn't complete

First of all, the SBMisc0 register has to be accessed with a 32b access. Then you can do it. This works better:

Code:

mov eax, 80006040h

mov dx,0cf8h

out dx,eax

;

mov dx,0cfch

in al,dx

or al,2

out dx,al

; now you have access to the gpio

xor al,al ; make all lower byte outputs

mov dx, 0320h

out dx,al

;now out to 0326h appears on the gpio port pins

Enjoy!

[aschampy]

Posted on May 12, 2005 at 11:34

Do you know how to check with their supplied excecutable for checking registers, mio, whether this enable is working?

Thanks,

Adam

Quote:

On 24-02-2004 at 01:33, Anonymous wrote:

Turns out, my suggestion wasn't complete

First of all, the SBMisc0 register has to be accessed with a 32b access. Then you can do it. This works better:

Code:

mov eax, 80006040h

mov dx,0cf8h

out dx,eax

;

mov dx,0cfch

in al,dx

or al,2

out dx,al

; now you have access to the gpio

xor al,al ; make all lower byte outputs

mov dx, 0320h

out dx,al

;now out to 0326h appears on the gpio port pins

Enjoy!