Programmable Devices
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20405 Discussions

EPCQ x4 electrical conflict


EPCQ datasheet says on page 43 that in x1 configuration chip's DATA2 and DATA3 pins are to be connected to Vcc. What happens if chip is set into x4 using configuration register? I guess chip will fry?


I am comparing to Winbond flash and document explicitly states that QE bit must never be set to 1.


I also have some credible circuit diagrams, and they have DATA2 and DATA3 pins connected to Vcc through 10k resistors.


So question: why EPCQ datasheet recommends connecting to Vcc directly, and is there any notice about what happens when chip is set into x4 mode?

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Hi EBryc,


Different flash devices vendor are designed and built with different features, thus do not be confuse thinking EPCQ and Windbond flash will behave/function exactly the same. If you are going to use EPCQ flash, please just refer to the EPCQ datasheet on how to use it and not compare with other flash device vendor.


The EPCQ device will not be damage regardless you set the Configuration mode to ASx1 or ASx4 in the Quartus project. Even if you set the Configuration mode to ASx4 in the Quartus project design but physically the EPCQ device is connected for ASx1 mode (DATA2 & DATA3 pin connected to VCC), the configuration will still work as ASx1 mode.





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