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Altera_Forum's avatar
Altera_Forum
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12 years ago

Passive Serial Tri-state

I am designing a Cyclone IV based board with an SPI interface that we would like to use to configure the FPGA with an MCU. We will configure the pins to toggle like Figure 8-16 (Device Handbook Vol ...
Altera_Forum's avatar
Altera_Forum
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12 years ago

The Data and DCLK are inputs in Passive Serial mode, so unless you specifically change the "Dual-Purpose Pins" setting in Quartus to make them GPIO's they will be inputs or tristated.

Check out: Assignments->Device->Device and Pin Options->Dual-Purpose Pins..

What pins are dual purpose may change from family to family. So make sure you are checking the pin settings for the device you need..

Pete