Digital signal 1 (DS1) is a T-carrier signaling scheme. DS1 is a widely used standard in telecommunications in North America and Japan to transmit voice and data between devices. E1 is sometimes used in place of DS1 outside of North America, Japan, and South Korea. Technically, DS1 is the logical bit pattern used over a physical T1 line; however, the terms "DS1" and "T1" are often used interchangeably. IC timers are semiconductor circuits that generate or set timing for electronics circuits