Table 164. 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
8e. Read Lock Bits(9)
0110110_00000000
0110111_00000000
xxxxxxx_xxxxxxxx
(5)
xxxxxxx_xxoooooo
8f. Read Fuses and Lock Bits
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
9a. Enter Signature Byte Read
9b. Load Address Byte
0100011_00001000
xxxxxxx_xxxxxxxx
xxxxxxx_xxxxxxxx
0000011_bbbbbbbb
9c. Read Signature Byte
0110010_00000000
0110011_00000000
xxxxxxx_xxxxxxxx
xxxxxxx_oooooooo
10a. Enter Calibration Byte Read
10b. Load Address Byte
0100011_00001000
xxxxxxx_xxxxxxxx
xxxxxxx_xxxxxxxx
0000011_bbbbbbbb
10c. Read Calibration Byte
0110110_00000000
0110111_00000000
xxxxxxx_xxxxxxxx
xxxxxxx_oooooooo
11a. Load No Operation Command
0100011_00000000
0110011_00000000
xxxxxxx_xxxxxxxx
xxxxxxx_xxxxxxxx
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 150 on page 336
7. The bit mapping for Fuses High byte is listed in Table 151 on page 337
8. The bit mapping for Fuses Low byte is listed in Table 152 on page 337
9. The bit mapping for Lock bits byte is listed in Table 148 on page 335
10. Address bits exceeding PCMSB and EEAMSB (Table 158 and Table 159) are don’t care
11. All TDI and TDO sequences are represented by binary digits (0b...).
360
ATmega640/1280/1281/2560/2561
2549A–AVR–03/05
ATMEL [ ATMEL ]
