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Altera_Forum
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9 years ago

Trouble interfacing FLASH pins to GPIO (retro game related)

Hey all, Just got an Altera DE1 dev board using the Cyclone II, and I'm working on a simple test that is literally just connecting the FLASH chip to the GPIO_0 bus. I'm not performing any logic...
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Altera_Forum
Icon for Honored Contributor rankHonored Contributor
9 years ago

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This instead routes FLASH pins A15-A21 to SNES pins A16-A22, which is needed for my test game to work. This also answers your last part, this address information is handled by the software in the ROM file.

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Your code uses flash address pins A15-20, not 21 (21 is pulled low) and SNES address A16-21 (you don't have addr 22 on the SNES side). Minor, but could this be the issue?

You could also have an IF assignment on SNES_ADDR(15) to route the address pins appropriately depending on whether it's high or low.