Hello,I have been attempting to program my FPGA to communicate with the SSRAM provided with the cyclone 3 starter board. However, when I attempt to assign pins H3 (FLASH_SRAM_DQ0) and D1 (FLASH_SRAM_DQ1) to my design I encounter errors in the fitter portion of the compilation. (Error: Can't place pins assigned to pin location Pin_D1 (IOPAD_X0_Y27_N7) and Error: Can't place pins assigned to pin location Pin_H3 (IOPAD_X0_Y22_N7)). Why do these errors occur, there does not seem to be any errors with any other pin assignments. Thanks. Andre
The said pins are pins used by the AS configuration interface, apparently you enabled AS configuration and reserved the pins. AS configuration isn't used by the starter board.
Thank you for your help. However, as I have a mediocre understanding of Altera FPGA programming and the Quartus II software I have no idea how to change this setting. Could you give me a few more details please, or at least tell me what AS stands for? Thanks.Andre
AS means active serial configuration, the starter board actually uses AP (active parallel) configuration, but it don't need to be set explicitely in Quartus.Assignments->Device->Device and Pin Options is the place for configuration settings. The important thing is that you set the Dual-Purpose Pins to regular i/o. The configuration scheme should be better set to passive serial to avoid conflicts with IO voltage.
Thanks again, but I appear to continue encountering the same problem despite these changes. I have tried changing the configuration to passive serial as suggested and had the very same errors. When I attempted to change the configuration to active parallel I got these errors for multiple pins including the two problem pins. Is there something else that i am missing? Thanks.Andre