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Altera_Forum
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14 years ago

Programming CPLD second time

Hello everybody, My test guys are having a problem programming our CPLD's, but only on the second time around when the CPLD already has a POF loaded. This would indicate to me that the CPL...
Altera_Forum's avatar
Altera_Forum
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14 years ago

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This would indicate to me that the CPLD has an issue with too much power

draw on the second programming attempt since the device is drawing power due to toggling flops and such or ?

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That sounds like a pretty random guess to me :)

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My idea was to use the DEV_OE pin to keep the CPLD quiet during programming, or are there other tricks here we can use ?

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You need to attack the problem systematically.

Lets start with your above hypothesis. Too much power. Ok, create a configuration that requires almost no power, eg., it blinks an LED. Download that configuration. Does the second configuration fail?

Its more likely that you have either; a power issue (voltage regulation), a clock issue, or JTAG signal integrity issues.

What CPLD are you using?

Cheers,

Dave