All ATtiny microcontrollers have a 3-byte signature code that identifies the device. This code can be read in both Serial and Parallel mode. The three bytes reside in a separate address space. For the device, the signature bytes are given in the following table.
| Device Name | Signature Bytes Address | ||
|---|---|---|---|
| 0x00 | 0x01 | 0x02 | |
| ATtiny202 | 0x1E | 0x91 | 0x23 |
| ATtiny402 | 0x1E | 0x92 | 0x27 |