The M382 is a custom gate array IC designed by Brian Rhodefer used in 11000-series plug-ins, where it serves three functions:
- Analog Control Voltage System (ACVS) management. Once the M382 has been given the values for each of the ACVS voltages, it takes care of sending data to the DAC and controlling the sample-and-hold circuits. The M382 periodically refreshes the sample-and-hold voltages without any involvement of the main microprocessor.
- sequencing the channels by controlling the amplifiers' output enable signals, as described on page 95 of the 11000-Series Plug-in to Main Frame Interface Manual
- implementing Serial Data Interface (SDI)
The SDI transmit logic in the M382 was heavily influenced by Jim Peterson's design for the SDI chip that is used in the 11000 mainframes. The SDI receiving logic in the M382 is a simpler than the receiving logic used in the mainframe SDI chip. The M382 has an interface that allows it to appear as an 8-bit peripheral in the external address space of a plug-in's 8051-family microcontroller.
M382 in bottom center, in 11A32