The Active Serial (AS) configuration scheme is supported in the 1 bit data width (AS x1) or the 4 bit data width (AS x4). The AS x4 scheme is supported only in Stratix® V devices. AS configuration can be performed using an Intel® FPGA serial configuration (EPCS) device or quad-serial configuration (EPCQ) device. During AS configuration, the Intel FPGA acts as the configuration host and the EPCS or EPCQ device acts as the configuration agent. The FPGA outputs the clock on the DCLK pin and receives the configuration data from the EPCS or EPCQ device on the data pin(s).
For more information, refer to the configuration chapter of the relevant Intel FPGA device in the Configuration Handbook.