User guide
Table Of Contents
- Features
- Pin Configurations
- Overview
- AVR CPU Core
- AVR ATmega162 Memories
- System Clock and Clock Options
- Power Management and Sleep Modes
- System Control and Reset
- Interrupts
- I/O-Ports
- Introduction
- Ports as General Digital I/O
- Alternate Port Functions
- Register Description for I/O-Ports
- Port A Data Register – PORTA
- Port A Data Direction Register – DDRA
- Port A Input Pins Address – PINA
- Port B Data Register – PORTB
- Port B Data Direction Register – DDRB
- Port B Input Pins Address – PINB
- Port C Data Register – PORTC
- Port C Data Direction Register – DDRC
- Port C Input Pins Address – PINC
- Port D Data Register – PORTD
- Port D Data Direction Register – DDRD
- Port D Input Pins Address – PIND
- Port E Data Register – PORTE
- Port E Data Direction Register – DDRE
- Port E Input Pins Address – PINE
- External Interrupts
- 8-bit Timer/Counter0 with PWM
- Timer/Counter0, Timer/Counter1, and Timer/Counter3 Prescalers
- 16-bit Timer/Counter (Timer/Counter1 and Timer/Counter3)
- Restriction in ATmega161 Compatibility Mode
- Overview
- Accessing 16-bit Registers
- Timer/Counter Clock Sources
- Counter Unit
- Input Capture Unit
- Output Compare Units
- Compare Match Output Unit
- Modes of Operation
- Timer/Counter Timing Diagrams
- 16-bit Timer/Counter Register Description
- Timer/Counter1 Control Register A – TCCR1A
- Timer/Counter3 Control Register A – TCCR3A
- Timer/Counter1 Control Register B – TCCR1B
- Timer/Counter3 Control Register B – TCCR3B
- Timer/Counter1 – TCNT1H and TCNT1L
- Timer/Counter3 – TCNT3H and TCNT3L
- Output Compare Register 1 A – OCR1AH and OCR1AL
- Output Compare Register 1 B – OCR1BH and OCR1BL
- Output Compare Register 3 A – OCR3AH and OCR3AL
- Output Compare Register 3 B – OCR3BH and OCR3BL
- Input Capture Register 1 – ICR1H and ICR1L
- Input Capture Register 3 – ICR3H and ICR3L
- Timer/Counter Interrupt Mask Register – TIMSK(1)
- Extended Timer/Counter Interrupt Mask Register – ETIMSK(1)
- Timer/Counter Interrupt Flag Register – TIFR(1)
- Extended Timer/Counter Interrupt Flag Register – ETIFR(1)
- 8-bit Timer/Counter2 with PWM and Asynchronous operation
- Serial Peripheral Interface – SPI
- USART
- Analog Comparator
- JTAG Interface and On-chip Debug System
- IEEE 1149.1 (JTAG) Boundary-scan
- Boot Loader Support – Read-While-Write Self-programming
- Features
- Application and Boot Loader Flash Sections
- Read-While-Write and No Read-While-Write Flash Sections
- Boot Loader Lock Bits
- Entering the Boot Loader Program
- Addressing the Flash During Self- programming
- Self-programming the Flash
- Performing Page Erase by SPM
- Filling the Temporary Buffer (Page Loading)
- Performing a Page Write
- Using the SPM Interrupt
- Consideration while Updating BLS
- Prevent Reading the RWW Section During Self- programming
- Setting the Boot Loader Lock Bits by SPM
- EEPROM Write Prevents Writing to SPMCR
- Reading the Fuse and Lock Bits from Software
- Preventing Flash Corruption
- Programming Time for Flash When Using SPM
- Simple Assembly Code Example for a Boot Loader
- ATmega162 Boot Loader Parameters
- Memory Programming
- Program And Data Memory Lock Bits
- Fuse Bits
- Signature Bytes
- Calibration Byte
- Parallel Programming Parameters, Pin Mapping, and Commands
- Parallel Programming
- Enter Programming Mode
- Considerations for Efficient Programming
- Chip Erase
- Programming the Flash
- Programming the EEPROM
- Reading the Flash
- Reading the EEPROM
- Programming the Fuse Low Bits
- Programming the Fuse High Bits
- Programming the Extended Fuse Bits
- Programming the Lock Bits
- Reading the Fuse and Lock Bits
- Reading the Signature Bytes
- Reading the Calibration Byte
- Parallel Programming Characteristics
- Serial Downloading
- SPI Serial Programming Pin Mapping
- Programming via the JTAG Interface
- Programming Specific JTAG Instructions
- AVR_RESET (0xC)
- PROG_ENABLE (0x4)
- PROG_COMMANDS (0x5)
- PROG_PAGELOAD (0x6)
- PROG_PAGEREAD (0x7)
- Data Registers
- Reset Register
- Programming Enable Register
- Programming Command Register
- Virtual Flash Page Load Register
- Virtual Flash Page Read Register
- Programming Algorithm
- Entering Programming Mode
- Leaving Programming Mode
- Performing Chip Erase
- Programming the Flash
- Reading the Flash
- Programming the EEPROM
- Reading the EEPROM
- Programming the Fuses
- Programming the Lock Bits
- Reading the Fuses and Lock Bits
- Reading the Signature Bytes
- Reading the Calibration Byte
- Electrical Characteristics
- ATmega162 Typical Characteristics
- Active Supply Current
- Idle Supply Current
- Power-down Supply Current
- Power-save Supply Current
- Standby Supply Current
- Pin Pull-up
- Pin Driver Strength
- Pin Thresholds and Hysteresis
- BOD Thresholds and Analog Comparator Offset
- Internal Oscillator Speed
- Current Consumption of Peripheral Units
- Current Consumption in Reset and Reset Pulsewidth
- Register Summary
- Instruction Set Summary
- Ordering Information
- Packaging Information
- Erratas
- Datasheet Change Log for ATmega162
- Table of Contents

63
ATmega162/V
2513E–AVR–09/03
Ports as General Digital
I/O
The ports are bi-directional I/O ports with optional internal pull-ups. Figure 29 shows a
functional description of one I/O-port pin, here generically called Pxn.
Figure 29. General Digital I/O
(1)
Note: 1. WPx, WDx, RRx, RPx, and RDx are common to all pins within the same port. clk
I/O
,
SLEEP, and PUD are common to all ports.
Configuring the Pin Each port pin consists of three register bits: DDxn, PORTxn, and PINxn. As shown in
“Register Description for I/O-Ports” on page 81, the DDxn bits are accessed at the
DDRx I/O address, the PORTxn bits at the PORTx I/O address, and the PINxn bits at
the PINx I/O address.
The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written
logic one, Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is config-
ured as an input pin.
If PORTxn is written logic one when the pin is configured as an input pin, the pull-up
resistor is activated. To switch the pull-up resistor off, PORTxn has to be written logic
zero or the pin has to be configured as an output pin. The port pins are tri-stated when a
reset condition becomes active, even if no clocks are running.
If PORTxn is written logic one when the pin is configured as an output pin, the port pin is
driven high (one). If PORTxn is written logic zero when the pin is configured as an out-
put pin, the port pin is driven low (zero).
When switching between tri-state ({DDxn, PORTxn} = 0b00) and output high ({DDxn,
PORTxn} = 0b11), an intermediate state with either pull-up enabled ({DDxn, PORTxn} =
0b01) or output low ({DDxn, PORTxn} = 0b10) must occur. Normally, the pull-up
clk
RPx
RRx
WRx
RDx
WDx
PUD
SYNCHRONIZER
WDx: WRITE DDRx
WRx: WRITE PORTx
RRx: READ PORTx REGISTER
RPx: READ PORTx PIN
PUD: PULLUP DISABLE
clk
I/O
: I/O CLOCK
RDx: READ DDRx
D
L
Q
Q
RESET
RESET
Q
Q
D
Q
Q
D
CLR
PORTxn
Q
Q
D
CLR
DDxn
PINxn
DATA BUS
SLEEP
SLEEP: SLEEP CONTROL
Pxn
I/O