The **IDT7142LA55CB** is a high-performance, low-power CMOS Dual-Port Static RAM (SRAM) manufactured by Integrated Device Technology (now part of Renesas Electronics). It is designed to allow two independent systems to access the same memory array simultaneously. --- ## 1. Technical Specifications The part number follows a specific nomenclature that defines its performance and physical characteristics. | Parameter | Specification | | :--- | :--- | | **Memory Type** | CMOS Dual-Port Static RAM (SRAM) | | **Density** | 16 Kbit (2K x 8 bits) | | **Access Time** | 55 ns | | **Power Grade** | LA (Low Power) | | **Package Type** | CB (48-pin Sidebraze Ceramic DIP) | | **Operating Temp** | Military (-55°C to +125°C) | | **Voltage Supply** | 5V ± 10% | --- ## 2. Core Functional Features ### Dual-Port Architecture This chip features two completely independent ports (Left and Right) with their own control, address, and I/O pins. This allows for: * **Asynchronous Access:** Both ports can read or write data at different times. * **Simultaneous Access:** Both ports can read the same memory location at the exact same time without interference. ### Arbitration and Semaphores To prevent data corruption during simultaneous writes to the same memory location, the IDT7142 includes: * **Busy Logic:** Hardware pins ($\overline{BUSY}$) that signal when one port has priority over the other. * **Interrupt Logic:** Ability to pass messages between processors using the memory as a mailbox. * **Full Hardware Support:** It manages collisions internally to ensure system stability. ### Low Power Consumption The "LA" designation indicates a low-power version, which is critical for military and aerospace applications where heat dissipation and battery life are concerns. It features: * **Active Power:** ~325mW (Typical) * **Standby Power:** ~1mW (Typical) --- ## 3. Pinout Categories The 48-pin Ceramic DIP package includes the following signal groups: | Group | Pins | Description | | :--- | :--- | :--- | | **Address** | $A_{0L} - A_{10L}$ / $A_{0R} - A_{10R}$ | Independent address lines for Left and Right ports. | | **Data I/O** | $I/O_{0L} - I/O_{7L}$ / $I/O_{0R} - I/O_{7R}$ | 8-bit bidirectional data lines for each port. | | **Control** | $\overline{CE}$, $\overline{OE}$, $R/\overline{W}$ | Chip Enable, Output Enable, and Read/Write control. | | **Arbitration** | $\overline{BUSY}$, $\overline{INT}$ | Conflict resolution and interrupt signaling. | --- ## 4. Typical Applications Because this specific part (CB package) is often rated for military temperatures and high reliability, it is found in: 1. **Multiprocessor Systems:** Linking two CPUs to share a common data buffer. 2. **Digital Signal Processing (DSP):** Buffering data between an ADC and a processor. 3. **Aerospace & Defense:** Avionics systems requiring high-reliability asynchronous data transfer. 4. **Legacy Industrial Control:** Communication between a main controller and a peripheral co-processor.