M74HC299B1R屬于集成電路（IC）的通用總線功能。由意法半導(dǎo)體集團(tuán)制造生產(chǎn)的M74HC299B1R通用總線功能通用總線功能系列產(chǎn)品是元件級產(chǎn)品，用于處理或操作一系列（通常為 8 個或更多）并行邏輯信號（稱為總線）。所執(zhí)行的功能包括臨時存儲要發(fā)送或接收的數(shù)據(jù)，執(zhí)行緩沖以允許輸出電流容量有限的器件（例如微處理器）通過遠(yuǎn)距離互連高速傳輸數(shù)據(jù)，以及調(diào)換或移動總線內(nèi)的位順序等。

DESCRIPTION

The M54/74HC299/323 are high speed CMOS 8-BIT PIPO SHIFT REGISTERS (3-STATE) fabri cated with silicon gate C2MOS technology.

They achieve the high speed operation similar to equivalent LSTTL while maintaining the CMOS low power consumption.

These devices have four modes (HOLD, SHIFT LEFT,SHIFT RIGHTand LOADDATA). Each mode is chosen by two function select inputs (S0, S1).

When one or both enable inputs, (G1, G2) are high, the eight input/output terminals are in the high impedance state ; however sequential operation or clearing of the register is not affected.

Clear function on the HC299 is asynchronous to CLOCK, while the HC323 is cleared synchronous to clock.

All inputs are equipped with protection circuits against static discharge and transient excess volt age.

■ HIGH SPEED

fMAX = 42 MHz (TYP.) AT VCC = 5V

■ LOW POWER DISSIPATION

ICC = 4 μA (MAX.) AT TA = 25 °C

■ HIGH NOISE IMMUNITY

VNIH = VNIL = 28 VCC (MIN.)

■ OUTPUT DRIVE CAPABILITY

10 LSTTL LOADS FOR QA’ TO QH’

15 LSTTL LOADS FOR QA TO QH

■ SYMMETRICAL OUTPUT IMPEDANCE

|IOH| = IOL = 6 mA (MIN.) FOR QA, TO QH,

|IOH| = IOL = 4 mA (MIN.) FOR QA, TO QH

■ BALANCED PROPAGATION DELAYS

tPLH = tPHL

■ WIDE OPERATING VOLTAGE RANGE

VCC (OPR) = 2 V TO 6 V

■ PIN AND FUNCTION COMPATIBLE WITH 54/74LS299