The DS1021 Programmable 8-Bit Silicon Delay Line consists of an 8-bit, user-programmable CMOS silicon integrated circuit. Delay values, programmed using either the 3-wire serial port or the 8-bit parallel port, can be varied over 256 equal steps. The faster model (-25) offers a maximum delay of 73.75 ns with an incremental delay of 0.25 ns, while the slower model (-50) has a maximum delay of 137.5 ns with an incremental delay of 0.5 ns. Both models have an inherent (step zero) delay of 10 ns. After the user-determined delay, the input logic state is reproduced at the output without inversion. The DS1021 is TTL- and CMOS-compatible, capable of driving 10 74LS-type loads, and features both rising and falling edge accuracy.