ATMEGA8A-MUR Atmel, ATMEGA8A-MUR Datasheet - Page 228

• Manufacturer Part Number: ATMEGA8A-MUR
• Description: MCU AVR 8KB FLASH 16MHZ 32QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8A-MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

24.2.1
24.3
24.4
8159D–AVR–02/11
Signature Bytes
Calibration Byte
Latching of Fuses
Table 24-4.
Notes:
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 3-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 ATmega8A the signature bytes are:
The ATmega8A stores four different calibration values for the internal RC Oscillator. These
bytes resides in the signature row High byte of the addresses 0x0000, 0x0001, 0x0002, and
0x0003 for 1, 2, 4, and 8MHz respectively. During Reset, the 1MHz value is automatically loaded
into the OSCCAL Register. If other frequencies are used, the calibration value has to be loaded
manually,
BODLEVEL
BODEN
SUT1
SUT0
CKSEL3
CKSEL2
CKSEL1
CKSEL0
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x93 (indicates 8KB Flash memory).
3. 0x002: 0x07 (indicates ATmega8A device).
Fuse Low
Byte
1. The default value of SUT1:0 results in maximum start-up time. See
2. The default setting of CKSEL3:0 results in internal RC Oscillator @ 1MHz. See
see “OSCCAL – Oscillator Calibration Register” on page 31
details.
page 25
Fuse Low Byte
Bit No.
7
6
5
4
3
2
1
0
for details.
Description
Brown out detector trigger level
Brown out detector enable
Select start-up time
Select start-up time
Select Clock source
Select Clock source
Select Clock source
Select Clock source
Default Value
1 (unprogrammed)
1 (unprogrammed, BOD disabled)
1 (unprogrammed)
0 (programmed)
0 (programmed)
0 (programmed)
0 (programmed)
1 (unprogrammed)
for details.
Table 8-9 on page 29
(1)
(2)
(2)
(2)
ATmega8A
(1)
(2)
Table 8-1 on
for
228