Signature Bytes

All AVR microcontrollers have a three-byte signature code, which identifies the device. This code can be read in both serial and parallel mode, also when the device is locked. The three bytes reside in a separate address space. For the device signature bytes, there are differences between ATmega48PA/88PA/168PA and ATmega48PB/88PB/168PB, see the table below for more detail.

Table 1. Device ID
Part Signature Bytes Address
0x000 0x001 0x002
ATmega48PA 0x1E 0x92 0x0A
ATmega48PB 0x1E 0x92 0x10
ATmega88PA 0x1E 0x93 0x0F
ATmega88PB 0x1E 0x93 0x16
ATmega168PA 0x1E 0x94 0x0B
ATmega168PB 0x1E 0x94 0x15