The UPD27C1001A-20 is a 1-megabit (128K x 8) EPROM (Erasable Programmable Read-Only Memory) manufactured by NEC (now Renesas Electronics). EPROMs are non-volatile memory devices that can be programmed and erased, typically using ultraviolet light.

Applications:

• Embedded Systems: Used to store firmware and program code in embedded systems such as industrial controllers, communication equipment, and consumer electronics.
• Microcontroller Program Storage: Used to store the program code for microcontrollers.
• Data Storage: Can be used for non-volatile data storage in applications where the data needs to be retained even when power is off.
• Bootloaders: Used to store bootloader code for computer systems and embedded devices.
• Legacy Systems: Found in older computer systems, arcade games, and other legacy equipment.

Features:

• 1 Megabit Capacity: Offers a storage capacity of 1,048,576 bits (128 kilobytes).
• Erasable Programmable Read-Only Memory: Can be programmed and erased using ultraviolet light.
• Fast Access Time: The "-20" suffix indicates a fast access time, typically 200ns (nanoseconds), allowing for quick data retrieval.
• Single 5V Power Supply: Operates on a single 5-volt power supply.
• TTL Compatible Inputs/Outputs: Compatible with TTL (Transistor-Transistor Logic) voltage levels.
• Static Operation: Requires no clock or refresh signals for data retention.

Benefits:

• Non-Volatile Storage: Retains data even when power is off.
• Reprogrammable: Can be erased and reprogrammed multiple times.
• Reliable Data Storage: Provides reliable data storage for critical applications.
• Easy to Interface: Easy to interface with microprocessors and microcontrollers.
• Cost-Effective Solution: Offers a cost-effective solution for non-volatile memory requirements.

The UPD27C1001A-20 requires a dedicated EPROM programmer to write data to the memory. Erasure is typically done using a UV EPROM eraser. Refer to the Renesas (formerly NEC) datasheet for detailed programming and erasure instructions, as well as timing diagrams and electrical characteristics.