ATMEGA8A-MUR Atmel, ATMEGA8A-MUR Datasheet - Page 231

• 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

24.7
24.7.1
24.7.2
8159D–AVR–02/11
Parallel Programming
Enter Programming Mode
Considerations for Efficient Programming
Table 24-10. Command Byte Bit Coding
The following algorithm puts the device in Parallel Programming mode:
Note, if the RESET pin is disabled by programming the RSTDISBL Fuse, it may not be possible
to follow the proposed algorithm above. The same may apply when External Crystal or External
RC configuration is selected because it is not possible to apply qualified XTAL1 pulses. In such
cases, the following algorithm should be followed:
The loaded command and address are retained in the device during programming. For efficient
programming, the following should be considered.
1. Apply 4.5 - 5.5V between V
2. Set RESET to “0” and toggle XTAL1 at least 6 times
3. Set the Prog_enable pins listed in
4. Apply 11.5 - 12.5V to RESET. Any activity on Prog_enable pins within 100ns after +12V
1. Set Prog_enable pins listed in
2. Apply 4.5 - 5.5V between V
3. Wait 100 ns.
4. Re-program the fuses to ensure that External Clock is selected as clock source
5. Exit Programming mode by power the device down or by bringing RESET pin to 0’b0.
6. Entering Programming mode with the original algorithm, as described above.
• The command needs only be loaded once when writing or reading multiple memory
• Skip writing the data value 0xFF, that is the contents of the entire EEPROM (unless the
• Address High byte needs only be loaded before programming or reading a new 256 word
locations.
EESAVE Fuse is programmed) and Flash after a Chip Erase.
window in Flash or 256byte EEPROM. This consideration also applies to Signature bytes
reading.
100 ns.
has been applied to RESET, will cause the device to fail entering Programming mode.
RESET.
(CKSEL3:0 = 0’b0000) and RESET pin is activated (RSTDISBL unprogrammed). If
Lock Bits are programmed, a chip erase command must be executed before changing
the fuses.
Command Byte
0000 1000
0000 0100
0000 0010
0000 0011
Command Executed
Read Signature Bytes and Calibration byte
Read Fuse and Lock Bits
Read Flash
Read EEPROM
CC
CC
and GND, and wait at least 100µs.
and GND simultaneously as 11.5 - 12.5V is applied to
Table 24-8 on page 230
Table 24-8 on page 230
to “0000”.
to “0000” and wait at least
ATmega8A
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