ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 286

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

27.8.10
286
Atmel ATmega48PA/88PA/168PA [Preliminary]
Reading the Signature Row from Software
The algorithm for reading the Fuse Low byte is similar to the one described above for reading
the Lock bits. To read the Fuse Low byte, load the Z-pointer with 0x0000 and set the BLBSET
and SELFPRGEN bits in SPMCSR. When an LPM instruction is executed within three cycles
after the BLBSET and SELFPRGEN bits are set in the SPMCSR, the value of the Fuse Low
byte (FLB) will be loaded in the destination register as shown below. Refer to
page 296
Similarly, when reading the Fuse High byte, load 0x0003 in the Z-pointer. When an LPM
instruction is executed within three cycles after the BLBSET and SELFPRGEN bits are set in
the SPMCSR, the value of the Fuse High byte (FHB) will be loaded in the destination register
as shown below. Refer to
Fuse High byte.
When reading the Extended Fuse byte, load 0x0002 in the Z-pointer. When an LPM instruction
is executed within three cycles after the BLBSET and SELFPRGEN bits are set in the
SPMCSR, the value of the Extended Fuse byte (EFB) will be loaded in the destination register
as shown below. Refer to
Extended Fuse byte.
Fuse and Lock bits that are programmed, will be read as zero. Fuse and Lock bits that are
unprogrammed, will be read as one.
To read the Signature Row from software, load the Z-pointer with the signature byte address
given in
tion 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 Lock bits 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.
Table 27-5.
Signature Byte
Device Signature Byte 1
Device Signature Byte 2
Device Signature Byte 3
RC Oscillator Calibration Byte
TSOFFSET - Temp Sensor Offset
TSGAIN - Temp Sensor Gain
Note:
Bit
Rd
Bit
Rd
Bit
Rd
Table 27-5
All other addresses are reserved for future use
for a detailed description and mapping of the Fuse Low byte.
Signature Row Addressing
FHB7
FLB7
7
7
7
–
and set the SIGRD and SPMEN bits in SPMCSR. When an LPM instruc-
FHB6
FLB6
Table 28-7 on page 297
Table 28-5 on page 296
6
6
6
–
FLB5
FHB5
5
5
5
–
FLB4
FHB4
4
4
4
–
for detailed description and mapping of the
for detailed description and mapping of the
FLB3
FHB3
EFB3
Z-Pointer Address
0x0000
0x0002
0x0004
0x0001
0x0005
0x0007
3
3
3
FLB2
FHB2
EFB2
2
2
2
FLB1
FHB1
EFB1
1
1
1
FLB0
FHB0
EFB0
Table 28-5 on
0
0
9223B–AVR–09/11
0