The GP1020 is a six-channel CMOS digital correlator which has been designed to work with the GP1010 L1-channel downconverter or other integrated circuits, and may be used to acquire and track the GPS C/A code or the GLONASS signals. For each of the six channels the GP1020 includes independent digital down-conversion to baseband, C/A code generation, correlation, and accumulate-and-dump registers. The GP1020 interfaces with a microprocessor via a 16-bit data bus to control the acquisition and tracking processes using the various registers on the chip.