The **7140LA55C** is a high-speed, low-power Dual-Port Static RAM (SRAM) integrated circuit. It is designed to provide independent access for two separate processors or buses to a shared memory space. --- ### ## Technical Specifications | Parameter | Specification | | :--- | :--- | | **Part Number** | 7140LA55C | | **Memory Density** | 8 Kbit (1K x 8 bits) | | **Access Time** | 55 ns (Nanoseconds) | | **Interface** | Parallel (Dual-Port) | | **Voltage Supply** | 4.5V to 5.5V (Standard 5V) | | **Package Type** | 48-pin Sidebraze DIP (Ceramic) | | **Operating Temp** | Commercial Range (0°C to +70°C) | | **Power Consumption** | Low Power ("LA" Version) | --- ### ### Key Features 1. **Dual-Port Memory Architecture:** The device allows two independent systems to read from and write to any location in the memory. This is critical for communication between asynchronous processors. 2. **On-Chip Hardware Logic:** It includes built-in hardware for arbitration: * **Busy Logic:** Signals when both ports attempt to access the same memory location simultaneously. * **Interrupt Logic:** Facilitates communication between the two ports. 3. **Low Power (LA):** The "LA" designation indicates a low-power version, which reduces power consumption during standby modes, making it suitable for battery-backed applications. 4. **Ceramic Packaging (C):** The "C" suffix often refers to the Ceramic Sidebraze package, which provides better heat dissipation and durability compared to plastic versions. --- ### ### Typical Pin Functions | Pin Names | Description | | :--- | :--- | | **A0L - A9L** | Address inputs for the Left port | | **A0R - A9R** | Address inputs for the Right port | | **I/O0L - I/O7L** | Data Input/Output for the Left port | | **CE, OE, R/W** | Chip Enable, Output Enable, and Read/Write controls | | **BUSY** | Output signal to indicate a port collision | | **INT** | Interrupt signal for inter-processor communication | --- ### ### Applications * **Multiprocessor Systems:** Linking two different microprocessors. * **Buffer Memory:** Acts as a high-speed buffer between a CPU and a peripheral. * **Digital Signal Processing (DSP):** Passing data between a DSP and a host controller. * **Network Equipment:** Handling packet data between different line cards.