74F674

Philips Semiconductors Product specification 16-bit serial/parallel-in, serial-out shift register (3-State) 74F674 FEATURES 16-bit serial I/O shift register 16-bit parallel-in/serial-out converter Recirculating serial shifting Common serial data I/O pin (3-State) DESCRIPTION The 74F674 is a 16-bit shift register with serial and parallel load capability and serial output. A single pin serves alternately as an input for serial entry or as a 3-State serial output. In the serial out mode the data recirculates in the register. Chip Select, Read/Write and Mode inputs provide control flexibility. The 74F674 operates in one of four modes, as indicated in the Function table. Hold: A High signal on the Chip Select (CS) input prevents clocking and forces the Serial Input/Output (SI/O) 3-State buffer into the high impedance state. Serial load: Data present on the SI/O pin shifts into the register on the falling edge of CP. Data enters the Q0 position and shifts toward Q15 on successive clocks. Serial output: The SI/O 3-State buffer is active and the register contents are shifted out from Q15 and simultaneously shifted back into Q0. Parallel load: Data present on D0–D15 is entered into the register on the falling edge of CP. The SI/O 3-State buffer is active and represents the Q15 output. To prevent false clocking, CP must be Low during a Low-to-High transition of CS. PIN CONFIGURATION CS CP R/W NC M SI/O D0 D1 D2 1 2 3 4 5 6 7 8 9 24 VCC 23 D15 22 D14 21 D13 20 D12 19 D1...