| A15 | 1 • | 28 | VCC |
| A12 | 2 | 27 | A14 |
| A7 | 3 | 26 | A13 |
| A6 | 4 | 25 | A8 |
| A5 | 5 | 24 | A9 |
| A4 | 6 | 23 | A11 |
| A3 | 7 | 22 | OE/VPP |
| A2 | 8 | 21 | A10 |
| A1 | 9 | 20 | CE |
| A0 | 10 | 19 | O7 |
| O0 | 11 | 18 | O6 |
| O1 | 12 | 17 | O5 |
| O2 | 13 | 16 | O4 |
| VSS | 14 | 15 | O3 |
| Pin | Symbol | Description |
|---|---|---|
| 1 | A15 | Address input |
| 2 | A12 | Address input |
| 3 | A7 | Address input |
| 4 | A6 | Address input |
| 5 | A5 | Address input |
| 6 | A4 | Address input |
| 7 | A3 | Address input |
| 8 | A2 | Address input |
| 9 | A1 | Address input |
| 10 | A0 | Address input |
| 11 | O0 | Data input/output |
| 12 | O1 | Data input/output |
| 13 | O2 | Data input/output |
| 14 | VSS | Ground |
| 15 | O3 | Data input/output |
| 16 | O4 | Data input/output |
| 17 | O5 | Data input/output |
| 18 | O6 | Data input/output |
| 19 | O7 | Data input/output |
| 20 | CE | Chip enable (active low) |
| 21 | A10 | Address input |
| 22 | OE/VPP | Output enable (active low)/Programming Voltage |
| 23 | A11 | Address input |
| 24 | A9 | Address input |
| 25 | A8 | Address input |
| 26 | A13 | Address input |
| 27 | A14 | Address input |
| 28 | VCC | positive supply voltage |
| Parameter | Value | Unit |
|---|---|---|
| Address to Output Delay | 90 (27C256-90) 100 (27C256-10) 120 (27C256-12) 150 (27C256-15) | ns |
| CE to Output Delay | 90 (27C256-90) 100 (27C256-10) 120 (27C256-12) 150 (27C256-15) | ns |
| OE to Output Delay | 40 (27C256-90) 40 (27C256-10) 50 (27C256-12) 60 (27C256-15) | ns |
| OE to Output High Impedance | 35 (27C256-90) 35 (27C256-10) 40 (27C256-12) 45 (27C256-15) | ns |
| Program Pulse Width | 95 to 105 | µs |
| OE /VPP Rise Time During Programming | 50 | ns |
Note: Data is maintained by an independent source and accuracy is not guaranteed. Check with the manufacturer's datasheet for up-to-date information.