problem using I/O ports

[dmerencio]

Posted on October 02, 2007 at 13:10

problem using I/O ports

[dmerencio]

Posted on September 27, 2007 at 14:26

Hello,

I was using the I/O port 0.15 in the STR710 FZ2 as a selector to program a Remote Loader. Using this pin the program were being stored correctly but the execution failed. I changed to the I/O port 1.2 and it worked fine.

As the port 0.15 is a ''wake-up pin'' or ''RTC alarm'' in the external interrupts which is not used in my program.

Does anyone have any idea if this could be the reason for this malfunction?

Thanks in advance,

Daniel

[jgoril]

Posted on September 28, 2007 at 05:47

Datasheet says and my practice confirms than P0.15 is input only. Using this pin like a general data input (not interrupt source) works fine. But if you want to use it like an output, it will not work...

[kaouther]

Posted on September 28, 2007 at 12:22

Dear Daniel,

The P0.15 is an input only could not be used as output. Please refer to table 3 in STR71x datasheet where you can find a note regarding this pin.

Regards.

[dmerencio]

Posted on October 01, 2007 at 13:37

I am using the port as input as a condition to jump or not, in the image attached you can see what I mean.

Then, the problem is that if I use the port 1.2 the download is done correctly and the execution as well. And if I use the port 0.15 the download is done correctly but the execution no. It seems that P0.15 performs an additional setting.

I hope I've been more clear this time.

Thanks and regards,

Daniel.

[ This message was edited by: daniMerencio on 01-10-2007 17:12 ]

________________

Attachments :

RemoteLoader.jpeg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HtNg&d=%2Fa%2F0X0000000aPA%2FO5G0bieD3d0qmmgOlWnQlOyaJfi24d3VDnUHBls.U1E&asPdf=false

[jgoril]

Posted on October 02, 2007 at 11:23

Are you speaking about the second decision (download or jump)? What level (H/L) is for download and what for jump?

[jgoril]

Posted on October 02, 2007 at 11:26

...and can you attach the schematics of your switching circuit?

[dmerencio]

Posted on October 02, 2007 at 11:51

I am refer to the first decision. If the P0.15 is active then launches the Remote Loader application else jumps to the user program.

[jgoril]

Posted on October 02, 2007 at 13:10

Have you checked your switching circuitry? Note - P0.15 is TTL level input (0.8 V for Low) while P1.2 is CMOS input (0.3*3.3 = 0.99 V for Low). By default, there is internal pull-up resistor on P1.2 input. If your problem really lies in P0.15 difference from others, it may be due to a poor Low level voltage...