SN74ABT3614-30PQ

FIFOs Memory Overview

The SN74ABT3614-30PQ is a high-speed, low-power BiCMOS bidirectional clocked FIFO memory featuring two independent 64 × 36 dual-port SRAMs. It supports clock frequencies up to 67 MHz with read-access times as fast as 10 ns. The device includes dynamic port-B bus sizing for 36-bit, 18-bit, and 9-bit formats, selectable big- or little-endian configurations, and three modes of byte-order swapping. Each FIFO has programmable almost-full and almost-empty flags synchronized to respective port clocks. Communication can bypass FIFOs via 36-bit mailbox registers. Parity checking and generation are supported per port. It operates from 0°C to 70°C in a 132-pin Quad Flat (PQ) package.

FIFOs Memory Feature Summary

• Two independent 64 × 36 clocked FIFOs buffer data in opposite directions with asynchronous or coincident free-running clocks.
• Dynamic port-B bus sizing allows configuration for 36-bit long words, 18-bit words, or 9-bit bytes with big- or little-endian selection.
• Mailbox-bypass registers enable direct communication between ports without queuing data through the FIFO arrays.
• Programmable almost-full and almost-empty flags provide precise status monitoring synchronized to specific port clocks.

FIFOs Memory Applications

• High-bandwidth computing applications requiring parity generation and checking
• Internetworking FIFO applications with advanced bus-matching and byte-swapping features
• Initializing DMA control using bypass registers

FIFOs Memory Procurement Notes

Verify the component is the SN74ABT3614-30PQ variant in the 132-pin PQ package. Confirm the operating temperature range matches the 0°C to 70°C specification. Ensure the logic family is Low-Power Advanced BiCMOS. Check datasheet revision SCBS126H for accurate terminal functions and timing constraints.

FIFOs Memory Selection Notes

Select this component when designing systems requiring bidirectional data buffering between microprocessors or buses with different bus widths. The dynamic bus sizing on Port B facilitates interfacing with peripherals using 9-bit, 18-bit, or 36-bit data paths. Use the mailbox registers for command and control information that must bypass the FIFO queue. Ensure clock frequencies do not exceed 67 MHz and access times meet the 10 ns requirement.

FIFOs Memory Part Context

The SN74ABT3614 belongs to the Texas Instruments SN74ABT series of logic devices. This series utilizes Low-Power Advanced BiCMOS technology to achieve high speed and low power consumption. The device is characterized for commercial operation temperatures. It is part of a family of FIFO memories designed for high-performance data buffering and synchronization tasks.

FIFOs Memory Replacement Considerations

Public confirmed substitute part numbers: None available in source material.

FIFOs Memory FAQ

How are the FIFO flags synchronized?

The full and almost-full flags are synchronized to the port clock that writes data to the array. The empty and almost-empty flags are synchronized to the port clock that reads data from the array. This two-stage synchronization reduces metastability when clocks are asynchronous.

What is the function of the mailbox registers?

Each FIFO has a 36-bit bypass register that allows data to pass directly between Port A and Port B without being queued in the FIFO memory. This is useful for transmitting command and control information.

How is parity handled in this device?

Parity is checked passively on each port based on the ODD/EVEN input setting. Parity generation can be selected for data read from each port via the PGA and PGB inputs, outputting the generated parity bit in the most-significant bit of each byte.