ATMEGA48A-PU Atmel, ATMEGA48A-PU Datasheet - Page 309

• Manufacturer Part Number: ATMEGA48A-PU
• Description: IC MCU AVR 4K FLASH 28PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48A-PU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• Controller Family/series: Atmega
• No. Of I/o's: 23
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 20MHz
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

27.7.10
27.7.11
8271C–AVR–08/10
Programming the Extended Fuse Bits
Programming the Lock Bits
1. A: Load Command “0100 0000”.
2. C: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3. Set BS1 to “1” and BS2 to “0”. This selects high data byte.
4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. Set BS1 to “0”. This selects low data byte.
The algorithm for programming the Extended Fuse bits is as follows (refer to
Flash” on page 305
1. 1. A: Load Command “0100 0000”.
2. 2. C: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
3. 3. Set BS1 to “0” and BS2 to “1”. This selects extended data byte.
4. 4. Give WR a negative pulse and wait for RDY/BSY to go high.
5. 5. Set BS2 to “0”. This selects low data byte.
Figure 27-5. Programming the FUSES Waveforms
The algorithm for programming the Lock bits is as follows (refer to
page 305
1. A: Load Command “0010 0000”.
2. C: Load Data Low Byte. Bit n = “0” programs the Lock bit. If LB mode 3 is programmed
3. Give WR a negative pulse and wait for RDY/BSY to go high.
The Lock bits can only be cleared by executing Chip Erase.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
(LB1 and LB2 is programmed), it is not possible to program the Boot Lock bits by any
External Programming mode.
RESET +12V
RDY/BSY
PAGEL
XTAL1
DATA
for details on Command and Data loading):
XA1
XA0
BS1
BS2
WR
OE
0x40
A
for details on Command and Data loading):
DATA
C
Write Fuse Low byte
XX
0x40
A
DATA
C
Write Fuse high byte
XX
”Programming the Flash” on
0x40
A
DATA
C
Write Extended Fuse byte
”Programming the
XX
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