SN74ALVC16270
12-BIT TO 24-BIT REGISTERED BUS EXCHANGER
WITH 3-STATE OUTPUTS

SCAS433 - OCTOBER 1993 - REVISED MARCH 1994

features

• EPIC^TM (Enhanced-Performance Implanted CMOS) Submicron Process
• Member of the Texas Instruments Widebus^TM Family
• Supports Unregulated Battery Operation Down to 2.7 V
• Typical V_OLP (Output Ground Bounce) < 0.8 V at V_CC = 3.3 V, T_A = 25°C
• Typical V_OHV (Output V_CC Overshoot) > 2 V at V_CC = 3.3 V, T_A = 25°C
• Bus-Hold On Data Inputs Eliminates the Need for External Pullup/Pulldown Resistors
• Packaged in Plastic Shrink Small-Outline (DL) and Thin Shrink Small-Outline (DGG) Packages

  EPIC and Widebus are trademarks of Texas Instruments Incorporated.

description

The SN74ALVC16270 is a 12-bit to 24-bit registered bus exchanger, which is intended for use in applications where data must be transferred from a narrow high-speed bus to a wide lower-frequency bus. It is designed specifically for low-voltage (3.3 V) V_CC operation.

The device provides for synchronous data exchange between the two ports. Data is stored in the internal registers on the low-to-high transition of the clock (CLK) input, provided that the appropriate inputs are low. The select ( line selects 1B or 2B data for the A outputs. For data transfer in the A-to-B direction, a two-stage pipeline is provided in the A to 1B path, with a single storage register in the A to 2B path. Proper control of the inputs allow two sequential 12-bit words to be presented synchronously as a 24-bit word on the B port. Data flow is controled by the active-low output enables (, ). These control pins are registered so that bus direction changes are synchronous with the clock.

Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.

The SN74ALVC16270 is available in TI's shrink small-outline (DL) and thin shrink small-outline (DGG) packages, which provide twice the I/O pin count and functionality of standard small-outline packages in the same printed-circuit-board area.

The SN74ALVC16270 is characterized for operation from -40°C to 85°C.