Configuration Handbook - Kamami.pl

Configuring Mercury, APEX 20K (2.5 V), ACEX 1K & FLEX 10K DevicesWhen the FPGA is in user-mode, you can initiate a reconfiguration bytransitioning the nCONFIG pin low-to-high. The nCONFIG pin should below for at least 21 μs for Mercury devices, 8 μs for APEX 20K devices and2 μs for ACEX 1K and Flex 10K devices. When nCONFIG is pulled low, theFPGA also pulls nSTATUS and CONF_DONE low and all I/O pins are tristated.Once nCONFIG returns to a logic high state and nSTATUS isreleased by the FPGA, reconfiguration begins.Figure 8–10 shows how to configure multiple devices using amicroprocessor. This circuit is similar to the PS configuration circuit for asingle device, except Mercury, APEX 20K (2.5 V), ACEX 1K, andFLEX 10K devices are cascaded for multi-device configuration.Figure 8–10. Multi-Device PS Configuration Using a MicroprocessorMemoryADDR DATA0MicroprocessorVCC (1)VCC (1)1 kΩ 1 kΩGNDMercury, APEX 20K (2.5-V),ACEX 1K or FLEX 10K Device 1MSEL0CONF_DONEnSTATUSnCEnCEODATA0nCONFIGDCLKMSEL1GNDMercury, APEX 20K (2.5-V),ACEX 1K or FLEX 10K Device 2MSEL0CONF_DONEnSTATUSnCEDATA0nCONFIGDCLKMSEL1nCEOGNDN.C.Note to Figure 8–10:(1) The pull-up resistor should be connected to a supply that provides an acceptable input signal for all devices in thechain.Altera Corporation 8–23August 2005 Configuration Handbook, Volume 1