The Intel UPI-41AH and UPI-42AH are general-purpose Universal Peripheral Interfaces that allow the designer to develop customized solutions for peripheral device control.
They are essentially ``slave microcontrollers, or microcontrollers with a slave interface included on the chip. Interface registers are included to enable the UPI device to function as a slave peripheral controller in the MCS Modules and iAPX family, as well as other 8-, 16-, and 32-bit systems.

* UPI-41: 6 MHz; UPI-42: 12.5 MHz
* Pin, Software and Architecturally Compatible with all UPI-41 and UPI-42 Products
* 8-Bit CPU plus ROM/OTP EPROM, RAM I/O, Timer/Counter and Clock in a
Single Package
* 2048 x 8 ROM/OTP, 256 x 8 RAM on UPI-42, 1024 x 8 ROM/OTP, 128 x 8 RAM on UPI-41, 8-Bit Timer/Counter, 18 Programmable I/O Pins
* One 8-Bit Status and Two Data Registers for Asynchronous Slave-to
Master Interface
* DMA, Interrupt, or Polled Operation Supported