ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 271

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

Figure 26-1. Addressing the Flash During SPM
26.2.1
26.2.2
9223B–AVR–09/11
EEPROM Write Prevents Writing to SPMCSR
Reading the Fuse and Lock Bits from Software
Z - REGISTER
PROGRAM MEMORY
BIT
PROGRAM
COUNTER
PAGE
15
Note:
Note that an EEPROM write operation will block all software programming to Flash. Reading
the Fuses and Lock bits from software will also be prevented during the EEPROM write opera-
tion. It is recommended that the user checks the status bit (EEPE) in the EECR Register and
verifies that the bit is cleared before writing to the SPMCSR Register.
It is possible to read both the Fuse and Lock bits from software. To read the Lock bits, load the
Z-pointer with 0x0001 and set the BLBSET and SELFPRGEN bits in SPMCSR. When an LPM
instruction is executed within three CPU cycles after the BLBSET and SELFPRGEN bits are
set in SPMCSR, the value of the Lock bits will be loaded in the destination register. The BLB-
SET and SELFPRGEN bits will auto-clear upon completion of reading the Lock bits or if no
LPM instruction is executed within three CPU cycles or no SPM instruction is executed within
four CPU cycles. When BLBSET and SELFPRGEN are cleared, LPM will work as described in
the Instruction set Manual.
PAGE ADDRESS
WITHIN THE FLASH
Bit
Rd
Atmel ATmega48PA/88PA/168PA [Preliminary]
ZPCMSB
PCMSB
1. The different variables used in
PCPAGE
7
–
(1)
ZPAGEMSB
PAGEMSB
6
–
PCWORD
WORD ADDRESS
WITHIN A PAGE
5
–
1
0
0
Figure 27-3
INSTRUCTION WORD
4
–
PAGE
are listed in
3
–
Table 28-11 on page
PCWORD[PAGEMSB:0]:
2
–
00
01
02
PAGEEND
LB2
1
LB1
0
299.
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