The **IDT6167LA55P** is a legacy high-speed Static Random Access Memory (SRAM) chip manufactured by Integrated Device Technology (IDT, now part of Renesas Electronics). It is widely used in vintage computing, industrial controllers, and timing-critical memory applications. --- ## 1. Technical Specifications The part number can be decoded to understand its specific electronic characteristics: | Parameter | Specification | | :--- | :--- | | **Memory Density** | 16 Kilobits (16K x 1) | | **Organization** | 16,384 words by 1 bit | | **Access Time (Speed)** | 55 nanoseconds (ns) | | **Power Version** | "LA" (Low Power version) | | **Package Type** | "P" (Plastic Dual In-line Package - PDIP) | | **Supply Voltage** | 5V ± 10% | | **I/O Logic** | TTL Compatible | --- ## 2. Key Features and Operation This component is an asynchronous SRAM, meaning it does not require a clock signal to operate. Its functionality is defined by its simple control pin interface: ### Control Pins * **A0 - A13 (Address Inputs):** Used to select one of the 16,384 memory locations. * **D_in / D_out (Data Lines):** Since this is a "x1" device, there is a single input pin and a single output pin for data. * **$\overline{WE}$ (Write Enable):** When LOW, data on $D_{in}$ is written to the selected address. * **$\overline{CS}$ (Chip Select):** When LOW, the chip is active. When HIGH, the chip enters a low-power standby mode. ### Power Characteristics The "LA" designation indicates that this chip features lower power consumption compared to the standard version, making it suitable for battery-backed applications (Non-volatile storage when paired with a battery controller). --- ## 3. Package and Pinout (PDIP-20) The **20-pin PDIP** is a through-hole package, common in 1980s and 1990s hardware. ```text +--U--+ A0 |1 20| VCC (+5V) A1 |2 19| A13 A2 |3 18| A12 A3 |4 17| A11 A4 |5 16| A10 A5 |6 15| A9 A6 |7 14| A8 Din |8 13| A7 /WE |9 12| Dout GND |10 11| /CS +-----+ ``` --- ## 4. Common Applications * **Cache Memory:** Used in early PC architectures (e.g., 386/486 systems) as high-speed cache. * **Buffer Memory:** Temporary data storage in networking or telecommunications equipment. * **Retro Computing:** Replacement parts for vintage synthesizers, arcade machines, and early home computers. * **Embedded Systems:** Simple data storage for 8-bit microcontrollers (8051, Z80).