Table 30-18. JTAG Programming Instruction (Continued)
Set (Continued) a = address high bits, b = address low bits, c = address extended bits, H = 0 - Low byte, 1 - High Byte,
o = data out, i = data in, x = don’t care
Instruction
TDI Sequence
TDO Sequence
Notes
0110010_00000000
0110011_00000000
xxxxxxx_xxxxxxxx
8d. Read Fuse Low Byte(8)
xxxxxxx_oooooooo
0110110_00000000
0110111_00000000
xxxxxxx_xxxxxxxx
8e. Read Lock Bits(9)
(5)
xxxxxxx_xxoooooo
0111010_00000000
0111110_00000000
0110010_00000000
0110110_00000000
0110111_00000000
xxxxxxx_xxxxxxxx
xxxxxxx_oooooooo
xxxxxxx_oooooooo
xxxxxxx_oooooooo
xxxxxxx_oooooooo
(5)
Fuse Ext. byte
Fuse High byte
Fuse Low byte
Lock bits
8f. Read Fuses and Lock Bits
9a. Enter Signature Byte Read
9b. Load Address Byte
0100011_00001000
xxxxxxx_xxxxxxxx
xxxxxxx_xxxxxxxx
0000011_bbbbbbbb
0110010_00000000
0110011_00000000
xxxxxxx_xxxxxxxx
9c. Read Signature Byte
xxxxxxx_oooooooo
10a. Enter Calibration Byte Read
10b. Load Address Byte
0100011_00001000
xxxxxxx_xxxxxxxx
xxxxxxx_xxxxxxxx
0000011_bbbbbbbb
0110110_00000000
0110111_00000000
xxxxxxx_xxxxxxxx
10c. Read Calibration Byte
xxxxxxx_oooooooo
0100011_00000000
0110011_00000000
xxxxxxx_xxxxxxxx
xxxxxxx_xxxxxxxx
11a. Load No Operation Command
Notes: 1. This command sequence is not required if the seven MSB are correctly set by the previous command sequence (which is
normally the case).
2. Repeat until o = “1”.
3. Set bits to “0” to program the corresponding Fuse, “1” to unprogram the Fuse.
4. Set bits to “0” to program the corresponding Lock bit, “1” to leave the Lock bit unchanged.
5. “0” = programmed, “1” = unprogrammed.
6. The bit mapping for Fuses Extended byte is listed in Table 30-3 on page 338
7. The bit mapping for Fuses High byte is listed in Table 30-4 on page 339
8. The bit mapping for Fuses Low byte is listed in Table 30-5 on page 339
9. The bit mapping for Lock bits byte is listed in Table 30-1 on page 337
10. Address bits exceeding PCMSB and EEAMSB (Table 30-7 and Table 30-8) are don’t care
11. All TDI and TDO sequences are represented by binary digits (0b...).
364
ATmega640/1280/1281/2560/2561
2549L–AVR–08/07
ATMEL [ ATMEL ]
