
303
ATmega64A [DATASHEET]
8160D–AVR–02/2013
7.
Write Fuse High byte using programming instruction 6f.
8.
Poll for Fuse write complete using programming instruction 6g, or wait for t
9.
Load data low byte using programming instructions 6h. A “0” will program the fuse, a “1” will unprogram the
fuse.
10. Write Fuse low byte using programming instruction 6i.
11. Poll for Fuse write complete using programming instruction 6j, or wait for t
28.9.22
Programming the Lock Bits
1.
Enter JTAG instruction PROG_COMMANDS.
2.
Enable Lock bit write using programming instruction 7a.
3.
Load data using programming instructions 7b. A bit value of “0” will program the corresponding Lock bit, a
“1” will leave the Lock bit unchanged.
4.
Write Lock bits using programming instruction 7c.
5.
Poll for Lock bit write complete using programming instruction 7d, or wait for t
28.9.23
Reading the Fuses and Lock Bits
1.
Enter JTAG instruction PROG_COMMANDS.
2.
Enable Fuse/Lock bit read using programming instruction 8a.
3.
To read all Fuses and Lock bits, use programming instruction 8f.
To only read Fuse Extended byte, use programming instruction 8b.
To only read Fuse High byte, use programming instruction 8c.
To only read Fuse Low byte, use programming instruction 8d.
To only read Lock bits, use programming instruction 8e.
28.9.24
Reading the Signature Bytes
1.
Enter JTAG instruction PROG_COMMANDS.
2.
Enable Signature byte read using programming instruction 9a.
3.
Load address 0x00 using programming instruction 9b.
4.
Read first signature byte using programming instruction 9c.
5.
Repeat steps 3 and 4 with address 0x01 and address 0x02 to read the second and third signature bytes,
respectively.
28.9.25
Reading the Calibration Byte
1.
Enter JTAG instruction PROG_COMMANDS.
2.
Enable Calibration byte read using programming instruction 10a.
3.
Load address 0x00 using programming instruction 10b.
4.
Read the calibration byte using programming instruction 10c.