A family of user-programmable peripherals, utilizing an integration strategy based on a programmable system device (PSD) concept, is described. Specifically, PSD is an efficient and highly configurable integration of high-density memory and LSI level logic blocks. The configurability is derived by providing programmable logic and programmable interconnect. PSDX is the first PSD family of programmable microcontroller peripherals; it integrates 256 kb to 1 Mb of EPROM, 16 kb of SRAM, a 28-input by 42-product term programmable logic device (PLD), and flexible I/O ports. This family is primarily targeted for embedded microcontroller applications. Using one PSD device it is possible to replace all the core peripherals in the system and, as a result, achieve a reduction in components, power dissipation, and overall system cost. The flexible architecture is achieved by providing 46 configuration options, which allows the PSD to interface with virtually any 8- or 16-b microcontroller. The integration is made possible by developing a special configurability and testability scheme. These parts are realized on a 1.2-µm CMOS EPROM process which includes an NVM module that provides the dedicated cells for the EPROM (10.6 µm2), PLD, and the configuration bits. The die size is 46 mm2 (for PSD2, which contains 512-kb EPROM) and is housed in a 44-pin package. Memory access time through the PLD is 120 ns and the PLD pin-to-pin delay is 35 ns at 4.5 V and 75.