FPGA configuration circuit including bus-based CRC register

摘要

A cyclic redundancy check (CRC) register is connected to the bi-directional bus and a packet processor in a configuration circuit of an FPGA. The CRC register performs transmission error detection functions based on the command/data transmissions to various registers connected to the bus, and based on the address information transmitted from the packet processor to an address/operand decoder used to enable the various registers to receive subsequent command/data words. The CRC register calculates a check-sum value in accordance with a predetermined equation. At any time during the transmission (e.g., halfway through configuration or at the end of configuration), a pre-calculated check-sum value is transmitted to the CRC register that represents an expected check-sum value at the selected time. The pre-calculated check-sum value is then compared with the check-sum value currently stored in the CRC register. If the pre-calculated check-sum value does not equal the current check-sum value, then an error signal is generated that notifies a user that a transmission error has occurred.