The AT28C64 is a low-power, high-performance 8,192 words by 8-bit nonvolatile electrically erasable and programmable read-only memory with popular, easy-to-use features. The device is manufactured with Atmel’s reliable nonvolatile technology. The AT28C64 is accessed like a Static RAM for the read or write cycles without the need for external components.
During a byte write, the address and data are latched internally, freeing the microprocessor address and data bus for other operations. Following the initiation of a write cycle, the device will go to a busy state and automatically clear and write the latched data using an internal control timer
28C64 Pinout
28C64 Pin Configuration
| Pin No | Pin Name | Description |
| 1 | NC | Not Connect |
| 2 | A12 | Address Pin 12 |
| 3 | A7 | Address Pin 7 |
| 4 | A6 | Address Pin 6 |
| 5 | A5 | Address Pin 5 |
| 6 | A4 | Address Pin 4 |
| 7 | A3 | Address Pin 3 |
| 8 | A2 | Address Pin 2 |
| 9 | A1 | Address Pin 1 |
| 10 | A0 | Address Pin 0 |
| 11 | I/O 0 | Data Inputs/Outputs 0 |
| 12 | I/O 1 | Data Inputs/Outputs 1 |
| 13 | I/O 2 | Data Inputs/Outputs 2 |
| 14 | GND | Ground Pin |
| 15 | I/O 3 | Data Inputs/Outputs 3 |
| 16 | I/O 4 | Data Inputs/Outputs 4 |
| 17 | I/O 5 | Data Inputs/Outputs 5 |
| 18 | I/O 6 | Data Inputs/Outputs 6 |
| 19 | I/O 7 | Data Inputs/Outputs 7 |
| 20 | CE’ | Chip Enable Pin |
| 21 | A10 | Address Pin 10 |
| 22 | OE’ | Output Enable |
| 23 | A11 | Address Pin 11 |
| 24 | A9 | Address Pin 9 |
| 25 | A8 | Address Pin 8 |
| 26 | NC | No Connection |
| 27 | WE’ | Write Enable Pin |
| 28 | VCC | Supply Voltage Pin |
28C64 Key Feature
- 5V ± 10% Supply
- CMOS and TTL Compatible Inputs and Outputs
- JEDEC Approved Byte-wide Pinout
- Commercial and Industrial Temperature Ranges
- Fast Read Access Time – 120 ns
- Fast Byte Write – 200 µs or 1 ms
- Self-timed Byte Write Cycle
- Internal Address and Data Latches
- Internal Control Timer
- Automatic Clear Before Write
- Direct Microprocessor Control
- READY/BUSY Open Drain Output
- DATA Polling
- Low Power
- 30 mA Active Current
- 100 µA CMOS Standby Current
- High Reliability
- Endurance: 10^4 or 10^5 Cycles
- Data Retention: 10 Years
You can download this datasheet for 28C64A 64K 150ns Parallel EEPROM – Datasheet from the link given below:
