SN74ALVCHG162282
18-BIT TO 36-BIT REGISTERED BUS EXCHANGER
WITH 3-STATE OUTPUTS


SCES094 - FEBRUARY 1997


 

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features

 

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description

The SN74ALVCHG162282 is an 18-bit to 36-bit registered bus exchanger. This device 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) VCC operation.

The device provides 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. For data transfer in the B-to-A direction, the select () input 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 1B path, with a single storage register in the 2B path. Data flow is controlled by the active-low output-enable () and direction-control (DIR) input. DIR is registered to synchronize the bus direction changes with the clock.

 

The A-port N-channel output transistors are sized at 450 m and the P-channel output transistors are sized at 700 m. All A-port outputs have 50- damping resistors. The B-port N-channel output transistors are sized at 225 m, and the P-channel output transistors are sized at 560 m. All B-port outputs have 20- damping resistors.

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

The switching characteristics are based on a 25-pF (A port) and 80-pF (B port) load, but are tested with the standard 50-pF load.

The SN74ALVCHG162282 is characterized for operation from 0°C to 70°C.