  The Prime-Cam instrument on the Fred Young Submillimeter Telescope (FYST) is
expected to be the largest deployment of millimeter and submillimeter sensitive
kinetic inductance detectors to date. To read out these arrays efficiently, a
microwave frequency multiplexed readout has been designed to run on the Xilinx
Radio Frequency System on a Chip (RFSoC). The RFSoC has dramatically improved
every category of size, weight, power, cost, and bandwidth over the previous
generation readout systems. We describe a baseline firmware design which can
read out four independent RF networks each with 500 MHz of bandwidth and 1000
detectors for ~30 W. The overall readout architecture is a combination of
hardware, gateware/firmware, software, and network design. The requirements of
the readout are driven by the 850 GHz instrument module of the 7-module
Prime-Cam instrument. These requirements along with other constraints which
have led to critical design choices are highlighted. Preliminary measurements
of the system phase noise and dynamic range are presented.
