ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 298

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

28.2.1
28.3
28.4
298
Signature Bytes
Calibration Byte
Atmel ATmega48PA/88PA/168PA [Preliminary]
Latching of Fuses
Table 28-9.
The status of the Fuse bits is not affected by Chip Erase. Note that the Fuse bits are locked if
Lock bit1 (LB1) is programmed. Program the Fuse bits before programming the Lock bits.
The fuse values are latched when the device enters programming mode and changes of the
fuse values will have no effect until the part leaves Programming mode. This does not apply to
the EESAVE Fuse which will take effect once it is programmed. The fuses are also latched on
Power-up in Normal mode.
All Atmel microcontrollers have a three-byte signature code which identifies the device. This
code can be read in both serial and parallel mode, also when the device is locked. The three
bytes reside in a separate address space. For the Atmel
nature bytes are given in
Table 28-10. Device ID
The Atmel ATmega48PA/88PA/168PA has a byte calibration value for the Internal RC Oscilla-
tor. This byte resides in the high byte of address 0x000 in the signature address space. During
reset, this byte is automatically written into the OSCCAL Register to ensure correct frequency
of the calibrated RC Oscillator.
Low Fuse Byte
CKDIV8
CKOUT
SUT1
SUT0
CKSEL3
CKSEL2
CKSEL1
CKSEL0
Note:
Part
Atmel ATmega48PA/88PA/168PA
Atmel ATmega88PA
Atmel ATmega168PA
(3)
(4)
1. The default value of SUT1...0 results in maximum start-up time for the default clock source.
2. The default setting of CKSEL3...0 results in internal RC Oscillator
3. The CKOUT Fuse allows the system clock to be output on PORTB0. See
4. See
See
on page 33
Buffer” on page 35
Fuse Low Byte
Table 9-12 on page 33
“System Clock Prescaler” on page 36
for details.
Table
Bit No
7
6
5
4
3
2
1
0
for details.
28-10.
Signature Bytes Address
0x000
0x1E
0x1E
0x1E
Description
Divide clock by 8
Clock output
Select start-up time
Select start-up time
Select Clock source
Select Clock source
Select Clock source
Select Clock source
for details.
for details.
0x001
0x92
0x93
0x94
®
ATmega48PA/88PA/168PA the sig-
Default Value
0 (programmed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
0 (programmed)
0 (programmed)
1 (unprogrammed)
0 (programmed)
at
8MHz. See
0x002
0x0A
0x0F
0x0B
“Clock Output
(1)
(2)
(2)
(2)
9223B–AVR–09/11
(1)
(2)
Table 9-11