
492
42073A-MCU Wireless-02/13
ATmega2564/1284/644RFR2
mapping of the Fuse Low byte.
Bit
7
6
5
4
3
2
1
0
Rd
FLB7
FLB6
FLB5
FLB4
FLB3
FLB2
FLB1
FLB0
Similarly, load 0x0003 in the Z-pointer for reading the Fuse High byte. When an (E)LPM
instruction is executed within three cycles after the BLBSET and SPMEN bits are set in
the SPMCSR, the value of the Fuse High byte (FHB) will be loaded in the destination
mapping of the Fuse High byte.
Bit
7
6
5
4
3
2
1
0
Rd
FHB7
FHB6
FHB5
FHB4
FHB3
FHB2
FHB1
FHB0
Load 0x0002 in the Z-pointer for reading the Extended Fuse byte. When an (E)LPM
instruction is executed within three cycles after the BLBSET and SPMEN bits are set in
the SPMCSR, the value of the Extended Fuse byte (EFB) will be loaded in the
description and mapping of the Extended Fuse byte.
Bit
7
6
5
4
3
2
1
0
Rd
-
EFB2
EFB1
EFB0
Fuse and Lock bits that are programmed will be read as zero. Fuse and Lock bits that
are un-programmed will be read as one.
30.6.10 Reading the Signature Row from Software
To read the Signature Row from software, load the Z-pointer with the signature byte
When a LPM instruction is executed within three CPU cycles after the SIGRD and
SPMEN bits are set in SPMCSR, the signature byte value will be loaded in the
destination register. The SIGRD and SPMEN bits will auto-clear upon completion of
reading the Signature Row or if no LPM instruction is executed within three CPU cycles.
When SIGRD and SPMEN are cleared, LPM will work as described in the Instruction
Set Manual. The Signature Row cannot be read during an EEPROM write/erase
operation.
Table 30-3. Signature Row Addressing
Signature Byte
Z-Pointer Address
(1)
Device Signature Byte 1
0x0000
Device Signature Byte 2
0x0002
Device Signature Byte 3
0x0004
RC Oscillator Calibration Byte
0x0001
User Signature Data – Page 1
0x0100 – 0x01FF
User Signature Data – Page 2
0x0200 – 0x02FF
User Signature Data – Page 3
0x0300 – 0x03FF
Note:
1. All other addresses are reserved for future use.