ATMEGA48A-PU Atmel, ATMEGA48A-PU Datasheet - Page 269

IC MCU AVR 4K FLASH 28PDIP

ATMEGA48A-PU

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

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
24.4
24.5
24.6
24.6.1
8271C–AVR–08/10
Software Break Points
Limitations of debugWIRE
Register Description
DWDR – debugWire Data Register
When designing a system where debugWIRE will be used, the following observations must be
made for correct operation:
• Pull-up resistors on the dW/(RESET) line must not be smaller than 10kΩ. The pull-up resistor
• Connecting the RESET pin directly to V
• Capacitors connected to the RESET pin must be disconnected when using debugWire.
• All external reset sources must be disconnected.
debugWIRE supports Program memory Break Points by the AVR Break instruction. Setting a
Break Point in AVR Studio
tion replaced by the BREAK instruction will be stored. When program execution is continued, the
stored instruction will be executed before continuing from the Program memory. A break can be
inserted manually by putting the BREAK instruction in the program.
The Flash must be re-programmed each time a Break Point is changed. This is automatically
handled by AVR Studio through the debugWIRE interface. The use of Break Points will therefore
reduce the Flash Data retention. Devices used for debugging purposes should not be shipped to
end customers.
The debugWIRE communication pin (dW) is physically located on the same pin as External
Reset (RESET). An External Reset source is therefore not supported when the debugWIRE is
enabled.
A programmed DWEN Fuse enables some parts of the clock system to be running in all sleep
modes. This will increase the power consumption while in sleep. Thus, the DWEN Fuse should
be disabled when debugWire is not used.
The following section describes the registers used with the debugWire.
The DWDR Register provides a communication channel from the running program in the MCU
to the debugger. This register is only accessible by the debugWIRE and can therefore not be
used as a general purpose register in the normal operations.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
Bit
Read/Write
Initial Value
is not required for debugWIRE functionality.
R/W
7
0
R/W
®
6
0
will insert a BREAK instruction in the Program memory. The instruc-
R/W
5
0
CC
R/W
will not work.
4
0
DWDR[7:0]
R/W
3
0
R/W
2
0
R/W
1
0
R/W
0
0
DWDR
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