ATMEGA88-20PJ Atmel, ATMEGA88-20PJ Datasheet - Page 70

IC MCU AVR 8K 5V 20MHZ 28-DIP

ATMEGA88-20PJ

Manufacturer Part Number
ATMEGA88-20PJ
Description
IC MCU AVR 8K 5V 20MHZ 28-DIP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets

Specifications of ATMEGA88-20PJ

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
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 6x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
28-DIP (0.300", 7.62mm)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
ATMEGA88-24PJ
ATMEGA88-24PJ
13. I/O-Ports
13.1
70
Overview
ATmega48/88/168
All AVR ports have true Read-Modify-Write functionality when used as general digital I/O ports.
This means that the direction of one port pin can be changed without unintentionally changing
the direction of any other pin with the SBI and CBI instructions. The same applies when chang-
ing drive value (if configured as output) or enabling/disabling of pull-up resistors (if configured as
input). Each output buffer has symmetrical drive characteristics with both high sink and source
capability. The pin driver is strong enough to drive LED displays directly. All port pins have indi-
vidually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O pins have
protection diodes to both V
acteristics” on page 302
Figure 13-1. I/O Pin Equivalent Schematic
All registers and bit references in this section are written in general form. A lower case “x” repre-
sents the numbering letter for the port, and a lower case “n” represents the bit number. However,
when using the register or bit defines in a program, the precise form must be used. For example,
PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O Regis-
ters and bit locations are listed in
Three I/O memory address locations are allocated for each port, one each for the Data Register
– PORTx, Data Direction Register – DDRx, and the Port Input Pins – PINx. The Port Input Pins
I/O location is read only, while the Data Register and the Data Direction Register are read/write.
However, writing a logic one to a bit in the PINx Register, will result in a toggle in the correspond-
ing bit in the Data Register. In addition, the Pull-up Disable – PUD bit in MCUCR disables the
pull-up function for all pins in all ports when set.
Using the I/O port as General Digital I/O is described in
71. Most port pins are multiplexed with alternate functions for the peripheral features on the
device. How each alternate function interferes with the port pin is described in
Functions” on page
nate functions.
Pxn
75. Refer to the individual module sections for a full description of the alter-
for a complete list of parameters.
CC
and Ground as indicated in
“Register Description” on page
C
pin
“Ports as General Digital I/O” on page
Figure
"General Digital I/O" for
13-1. Refer to
86.
See Figure
R
Details
pu
Logic
“Electrical Char-
“Alternate Port
2545S–AVR–07/10

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