ATMEGA168-15AZ Atmel, ATMEGA168-15AZ Datasheet - Page 260

• Manufacturer Part Number: ATMEGA168-15AZ
• Description: MCU AVR 16K FLASH 15MHZ 32-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA168-15AZ

• Package / Case: 32-TQFP, 32-VQFP
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 23
• Eeprom Size: 512 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Program Memory Size: 16KB (16K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: I²C, SPI, UART/USART
• Core Size: 8-Bit
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 16MHz
• Interface Type: 2-Wire/USART/Serial
• Total Internal Ram Size: 1KB
• # I/os (max): 23
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 32
• Package Type: TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.1.4
23.1.5
260
ATmega48/88/168 Automotive
Preventing Flash Corruption
Programming Time for Flash when Using SPM
Similarly, when reading the Extended Fuse byte (EFB), 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 will be loaded in the destination register as
shown below. See
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.
During periods of low V
too low for the CPU and the Flash to operate properly. These issues are the same as for board
level systems using the Flash, and the same design solutions should be applied.
A Flash program corruption can be caused by two situations when the voltage is too low. First, a
regular write sequence to the Flash requires a minimum voltage to operate correctly. Secondly,
the CPU itself can execute instructions incorrectly, if the supply voltage for executing instructions
is too low.
Flash corruption can easily be avoided by following these design recommendations (one is
sufficient):
The calibrated RC Oscillator is used to time Flash accesses.
gramming time for Flash accesses from the CPU.
Table 23-1.
Bit
Rd
Flash write (Page Erase, Page Write, and
write Lock bits by SPM)
1. Keep the AVR RESET active (low) during periods of insufficient power supply voltage.
2. Keep the AVR core in Power-down sleep mode during periods of low V
This can be done by enabling the internal Brown-out Detector (BOD) if the operating
voltage matches the detection level. If not, an external low V
can be used. If a reset occurs while a write operation is in progress, the write operation
will be completed provided that the power supply voltage is sufficient.
vent the CPU from attempting to decode and execute instructions, effectively protecting
the SPMCSR Register and thus the Flash from unintentional writes.
SPM Programming Time
FHB7
Symbol
7
Table 25-5 on page 280
CC
FHB6
, the Flash program can be corrupted because the supply voltage is
6
FHB5
5
Min Programming Time
for detailed description and mapping of the Extended
FHB4
4
3.7 ms
FHB3
3
FHB2
Table 24-5
2
CC
reset protection circuit
Max Programming Time
FHB1
1
shows the typical pro-
CC
. This will pre-
4.5 ms
FHB0
0
7530I–AVR–02/10