CDCE906-706PERFEVM

Keith Davis

I have the CECD906-706PERFEVM board, connected through a parallel port. The board wakes up with the default 27MHz output, but when I attempt to change the settings by selecting 'write register', I get 'write error' and no change in the output. I can see SDA and SCL activity (J17) on the oscilloscope, so I believe my parallel port is working. Any ideas?

over 9 years ago

0 Patrick Kammermayer over 9 years ago

TI__Expert 5325 points

Hello Keith,

J17 is before the level translator on the parallel port side. Can you please check if the signals go through? You can do this at R27 and R37.

Best regards,

Patrick

0 Keith Davis over 9 years ago in reply to Patrick Kammermayer

Prodigy 50 points

Hello Patrick,

Thank you for pointing me in the correct direction. I thought the cable I dug up was a printer cable, but it did not have a connection for J18-18. So, no /CE for the 74LV125 buffer IC and no signals on R27 and R37. I found an actual printer cable and can now write to the board.

Best Regards,

Keith

0 Patrick Kammermayer over 9 years ago in reply to Keith Davis

TI__Expert 5325 points

Hello Keith,
that sounds great it is working for you now! You can tie the !CE to VDD of the decoupling cap close-by. Then you are independant of the cable and you can also connect an MCU like MSP430 or Sitara to the pin header to test your own firmware.

Best regards,
Patrick

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CDCE906-706PERFEVM