ATMEGA48PA-AN Atmel, ATMEGA48PA-AN Datasheet - Page 298

• Manufacturer Part Number: ATMEGA48PA-AN
• Description: MCU AVR 4KB FLASH 20MHZ 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48PA-AN

• 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 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

27.2.1
27.3
27.4
8161D–AVR–10/09
Signature Bytes
Calibration Byte
Latching of Fuses
Table 27-9.
Note:
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 ATmega48PA/88PA/168PA/328P the signa-
ture bytes are given in
Table 27-10. Device ID
The ATmega48PA/88PA/168PA/328P has a byte calibration value for the Internal RC Oscillator.
This byte resides in the high byte of address 0x000 in the signature address space. During reset,
Low Fuse Byte
CKDIV8
CKOUT
SUT1
SUT0
CKSEL3
CKSEL2
CKSEL1
CKSEL0
Part
ATmega48PA
ATmega88PA
ATmega168PA
ATmega328P
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 @ 8 MHz. See
3. The CKOUT Fuse allows the system clock to be output on PORTB0. See
4. See
(3)
(4)
See
page 33
on page 35
Fuse Low Byte
Table 8-12 on page 33
”System Clock Prescaler” on page 35
for details.
for details.
Table
Bit No
27-10.
7
6
5
4
3
2
1
0
ATmega48PA/88PA/168PA/328P
Signature Bytes Address
0x000
0x1E
0x1E
0x1E
0x1E
for details.
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.
0x001
0x92
0x93
0x94
0x95
Default Value
0 (programmed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
0 (programmed)
0 (programmed)
1 (unprogrammed)
0 (programmed)
”Clock Output Buffer”
0x002
0x0A
0x0F
0x0B
0x0F
(1)
(2)
(2)
(2)
Table 8-11 on
(1)
(2)
298