Added/Modified Pin Functionality

There are two package types that are compatible with ATmega48/88/168 and ATmega48PB/88PB/168PB. This section will compare the pin-out of the TQFP package type. For the other compatible package type, MLF/VFQFN, refer to the data sheet chapters "Ordering Information" and "Packaging Information".

ATmega48PB/88PB/168PB introduces four additional GPIO pins; PORTE [3:0]. The different pins are described in Table 1 and the pin-out for each device are shown in Figure 1 and Figure 2.

The 32-pin MLF/VQFN pin-out can be found in the Pin Configurations section in the ATmega48PB/88PB/168PB data sheet.

Figure 1. ATmega48/88/168 - 32-Pin TQFPATmega48PA/88PA/168PA - 32-pin TQFP
Figure 2. ATmega48PB/88PB/168PB - 32-Pin TQFPATmega48PB/88PB/168PB - 32-pin TQFP

GPIO pins PE2 and PE3 are added to Pin19 and Pin22. PE2 and PE3 are multiplexed with ADC6 and ADC7.

Pin3 (GND) and Pin6 (VCC) are replaced by PE0 and PE1 respectively. PE0 is multiplexed with ACO.

Table 1. Pin Functionality Difference
32-Pin TQFP Package ATmega48/88/168 ATmega48PB/88PB/168PB
Pin3 GND PE0/ACO
Pin6 VCC PE1
Pin19 ADC6 ADC6/PE2
Pin22 ADC7 ADC7/PE3
To use the ATmega48PB/88PB/168PB device as a drop-in replacement for the ATmega48/88/168 the following conditions must meet: