Datasheet

Figure 32-5. Mapping Between BS1, BS2 and the Fuse and Lock Bits During Read
Lock Bits
0
1
BS2
Fuse High Byte
0
1
BS1
DATA
Fuse Low Byte
0
1
BS2
Extended Fuse Byte
32.8.13 Reading the Signature Bytes
The algorithm for reading the Signature bytes is as follows (refer to 32.8.4 Programming the Flash for
details on command and address loading):
1. Step A: Load Command “0000 1000”.
2. Step B: Load Address Low Byte (0x00 - 0x02).
3. Set OE to “0”, and BS1 to “0”. The selected Signature byte can now be read at DATA.
4. Set OE to “1”.
32.8.14 Reading the Calibration Byte
The algorithm for reading the Calibration byte is as follows (refer to 32.8.4 Programming the Flash for
details on command and address loading):
1. Step A: Load Command “0000 1000”.
2. Step B: Load Address Low Byte, 0x00.
3. Set OE to “0”, and BS1 to “1”. The Calibration byte can now be read at DATA.
4. Set OE to “1”.
32.8.15 Parallel Programming Characteristics
For characteristics of the Parallel Programming, refer to Parallel Programming Characteristics.
Related Links
33.9 Parallel Programming Characteristics
32.9 Serial Downloading
Both the Flash and EEPROM memory arrays can be programmed using the serial SPI bus while RESET
is pulled to GND. The serial interface consists of pins SCK, MOSI (input) and MISO (output). After
RESET is set low, the programming enable instruction needs to be executed first before the program/
erase operations can be executed.
ATmega48PA/88PA/168PA
Memory Programming (MEMPROG)
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40002011A-page 378