74HC_HCT194_CNV

General description

The 74HC/HCT194 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A.

The functional characteristics of the 74HC/HCT194 4-bit bidirectional universal shift registers are indicated in the logic diagram and function table. The registers are fully synchronous.

The '194' design has special features which increase the range of application. The synchronous operation of the device is determined by the mode select inputs (S₀, S₁).
As shown in the mode select table, data can be entered and shifted from left to right (Q₀® Q₁® Q₂ , etc.) or, right to left (Q₃® Q₂® Q₁ , etc.) or parallel data can be entered, loading all 4 bits of the register simultaneously. When both S0 and S1 are LOW, existing data is retained in a hold (?do nothing?) mode. The first and last stages provide D-type serial data inputs (D_SR, D_SL) to allow multistage shift right or shift left data transfers without interfering with parallel load operation.

Mode select and data inputs are edge-triggered, responding only to the LOW-to-HIGH transition of the clock (CP). Therefore, the only timing restriction is that the mode control and selected data inputs must be stable one set-up time prior to the positive transition of the clock pulse.

The four parallel data inputs (D₀ to D₃) are D-type inputs. Data appearing on the D₀ to D₃ inputs, when S₀ and S₁ are HIGH, is transferred to the Q₀ to Q₃ outputs respectively, following the next LOW-to-HIGH transition of the clock. When LOW, the asynchronous master reset (MR) overrides all other input conditions and forces the Q outputs LOW.

The '194' is similar in operation to the '195' universal shift register, with added features of shift-left without external connections and hold ('do nothing') modes of operation.

Features

• Shift-left and shift-right capability
• Synchronous parallel and serial data transfer
• Easily expanded for both serial and parallel operation
• Asynchronous master reset
• Hold ('do nothing') mode
• Output capability: standard
• I_CC category: MSI

Products/packages

Quality/reliability/chemical content

Quality and reliability disclaimer

Pricing/ordering/availability

Applications

• Serial-to-parallel data conversion
• Remote control holding register

Design support

Support Documents

HCT_USER_GUIDE; HC/T User Guide (1997-11-01)

Parametrics/similar products

Similar products
74HC_HCT194_CNV links to the similar products page containing an overview of products that are similar in function or related to the type number(s) as listed on this page. The similar products page includes products from the same catalog tree(s), relevant selection guides and products from the same functional category.

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer