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Altera_Forum
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18 years ago

nCE signal behavour

Hi everybody, there is a small question about nCE behavour. It is safe to change nCE signal after Cyclone II FPGA have been configured? Or the Cyclone II FPGA will be reset in this case? T...
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Altera_Forum
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18 years ago

Julianus,

The Cyclone II handbook (see http://www.altera.com/literature/hb/cyc2/cyc2_cii51013.pdf Page 66) states that nCE must be held low during configuration, initialization & user mode.

Additional information can be found in the Cyclone II pinout documents (see for example http://www.altera.com/literature/dp/cyclone2/ep2c15a.pdf). Here it is mentioned:

When nCE is low, the device is enabled. When nCE is high, the device is disabled.

Clearly, you must ensure that nCE is held low after configuration.

--jmv