12 ns EE PLD in a 20-pin DIP — legacy logic glue
The Microchip ATF16V8CZ-12PC is an electrically erasable programmable logic device (EE PLD) from the 16V8 family, delivering a 12 ns pin-to-pin propagation delay from input to combinatorial output. Operating from a single 5V supply, the ATF16V8CZ-12PC is compatible with legacy 5V TTL and CMOS logic families. The 20-pin DIP package (0.300" width) mates with standard DIP sockets or through-hole solder pads, common in industrial controllers, telecom line cards, and test equipment from the 1990s through early 2000s.
Microchip lists the ATF16V8CZ-12PC as Obsolete.
5V-only operation and 12 ns timing margin
The 12 ns propagation delay is the combinatorial input-to-output time at 5V supply and 25°C. In a typical address-decoding or state-machine application, this sets the maximum logic depth before the system clock edge. For a 50 MHz clock (20 ns period), a single 12 ns PLD stage leaves 8 ns of timing margin for interconnect and register setup — workable but tight. At elevated temperature or with supply droop, the delay increases; budget 15–18 ns worst-case for reliable operation across the industrial range. The 8 macrocells can implement up to 8 registered flip-flops or 8 combinatorial sums-of-products, or a mix. Each macrocell includes a programmable output polarity and a configurable output type (registered, combinatorial, or tri-state). This is sufficient for simple glue logic: address decoders, bus arbiters, state machines with fewer than 8 states, or PAL/GAL replacement in existing sockets.