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Altera_Forum
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17 years ago

Cyclone III EPCS16 config FAIL

Hi all, I'm working on a revision of a PCB that contains a total of 12 EP3C16Q240C8N all configured with the same object file as in figure 10-6 of the datasheet. As it stands now, the configur...
Altera_Forum's avatar
Altera_Forum
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17 years ago

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I think the problem is being caused by a buffer that is connected to the lines.

There is a std 74lvth244 buffer that both signals are connected to. I think

the bus hold circuitry is latching the inputs low on power on. I am going to replace the buffers with a non-bus hold type and see if it fixes my problem.

Phil

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I have verified that our config problem was caused by a buffer with bus hold circuitry.

We disconnected the buffer and the config lines were pulled up normally. We will switch to a buffer without bus hold circuitry.