Configuration Handbook - Kamami.pl

Using Flash Memory to Configure FPGAsAfter a command is executed, the controller returns to idle mode andwaits for the next command. Figure 10–2 shows the controller statemachine.Figure 10–2. Flash Memory Controller State MachinePORCheck if FlashMemory has beenProgrammedYesConfigureAPEX DevicesNoNo CMDIDLEWait for Commandsfrom PCCMD from PCDoneProgrammingDecode CommandProgram FlashMemoryConfigureAPEX DevicesFlash Memory Controller FunctionalityThe controller writes a byte to a special location in the flash memorywhen it programs the memory. After POR, the controller checks thisspecial location in the flash memory to see if the byte is written there ornot.If the byte is written, then the flash memory has been programmed andthe controller can proceed to configuring the FPGAs by reading data fromthe flash memory. If this byte is not there or the value is not as expected,the controller will go idle and wait to be programmed by the PC ormicroprocessor.Altera Corporation 10–3April 2007 Configuration Handbook, Volume 2