The MT9085 Parallel Access Circuit (PAC) provides an interface between an 8 bit, parallel time division multiplexed bus and a serial time division multiplexed bus. A single PAC device will accept data clocked out on the parallel bus of the Mitel MT9080 (SMX) and output it on 32/16 time division multiplexed serial bus streams. A second device can be configured to perform the conversion from the serial format into an SMX compatible parallel format. The time division, serial multiplexed streams may operate at 2.048 Mbit/s or at 4.096 Mbit/s. The PAC generates all framing signals required by the SMX for 1024 and 2048 channel configurations.