Datasheet
Table Of Contents
- Features
- 1. Pin Configurations
- 2. Overview
- 3. Resources
- 4. Data Retention
- 5. About Code Examples
- 6. Capacitive touch sensing
- 7. AVR CPU Core
- 8. AVR Memories
- 9. System Clock and Clock Options
- 10. Power Management and Sleep Modes
- 11. System Control and Reset
- 12. Interrupts
- 13. I/O Ports
- 13.1 Overview
- 13.2 Ports as General Digital I/O
- 13.3 Alternate Port Functions
- 13.4 Register Description
- 13.4.1 SFIOR – Special Function I/O Register
- 13.4.2 PORTA – Port A Data Register
- 13.4.3 DDRA – Port A Data Direction Register
- 13.4.4 PINA – Port A Input Pins Address
- 13.4.5 PORTB – Port B Data Register
- 13.4.6 DDRB – Port B Data Direction Register
- 13.4.7 PINB – Port B Input Pins Address
- 13.4.8 PORTC – Port C Data Register
- 13.4.9 DDRC – Port C Data Direction Register
- 13.4.10 PINC – Port C Input Pins Address
- 13.4.11 PORTD – Port D Data Register
- 13.4.12 DDRD – Port D Data Direction Register
- 13.4.13 PIND – Port D Input Pins Address
- 14. External Interrupts
- 15. 8-bit Timer/Counter0 with PWM
- 16. Timer/Counter0 and Timer/Counter1 Prescalers
- 17. 16-bit Timer/Counter1
- 17.1 Features
- 17.2 Overview
- 17.3 Accessing 16-bit Registers
- 17.4 Timer/Counter Clock Sources
- 17.5 Counter Unit
- 17.6 Input Capture Unit
- 17.7 Compare Match Output Unit
- 17.8 Modes of Operation
- 17.9 Timer/Counter Timing Diagrams
- 17.10 Register Description
- 17.10.1 TCCR1A – Timer/Counter1 Control Register A
- 17.10.2 TCCR1B – Timer/Counter1 Control Register B
- 17.10.3 TCNT1H and TCNT1L – Timer/Counter1
- 17.10.4 OCR1AH and OCR1AL – Output Compare Register 1 A
- 17.10.5 OCR1BH and OCR1BL – Output Compare Register 1 B
- 17.10.6 ICR1H and ICR1L – Input Capture Register 1
- 17.10.7 TIMSK – Timer/Counter Interrupt Mask Register(1)
- 17.10.8 TIFR – Timer/Counter Interrupt Flag Register
- 18. 8-bit Timer/Counter2 with PWM and Asynchronous Operation
- 18.1 Features
- 18.2 Overview
- 18.3 Timer/Counter Clock Sources
- 18.4 Counter Unit
- 18.5 Output Compare Unit
- 18.6 Compare Match Output Unit
- 18.7 Modes of Operation
- 18.8 Timer/Counter Timing Diagrams
- 18.9 Asynchronous Operation of the Timer/Counter
- 18.10 Timer/Counter Prescaler
- 18.11 Register Description
- 18.11.1 TCCR2 – Timer/Counter Control Register
- 18.11.2 TCNT2 – Timer/Counter Register
- 18.11.3 OCR2 – Output Compare Register
- 18.11.4 ‘ASSR – Asynchronous Status Register
- 18.11.5 TIMSK – Timer/Counter Interrupt Mask Register
- 18.11.6 TIFR – Timer/Counter Interrupt Flag Register
- 18.11.7 SFIOR – Special Function IO Register
- 19. SPI – Serial Peripheral Interface
- 20. USART
- 20.1 Features
- 20.2 Overview
- 20.3 Clock Generation
- 20.4 Frame Formats
- 20.5 USART Initialization
- 20.6 Data Transmission – The USART Transmitter
- 20.7 Data Reception – The USART Receiver
- 20.8 Asynchronous Data Reception
- 20.9 Multi-processor Communication Mode
- 20.10 Accessing UBRRH/ UCSRC Registers
- 20.11 Register Description
- 20.12 Examples of Baud Rate Setting
- 21. Two-wire Serial Interface
- 22. Analog Comparator
- 23. Analog to Digital Converter
- 24. JTAG Interface and On-chip Debug System
- 25. IEEE 1149.1 (JTAG) Boundary-scan
- 26. Boot Loader Support – Read-While-Write Self-Programming
- 26.1 Features
- 26.2 Overview
- 26.3 Application and Boot Loader Flash Sections
- 26.4 Read-While-Write and no Read-While-Write Flash Sections
- 26.5 Boot Loader Lock Bits
- 26.6 Entering the Boot Loader Program
- 26.7 Addressing the Flash during Self-Programming
- 26.8 Self-Programming the Flash
- 26.8.1 Performing Page Erase by SPM
- 26.8.2 Filling the Temporary Buffer (Page Loading)
- 26.8.3 Performing a Page Write
- 26.8.4 Using the SPM Interrupt
- 26.8.5 Consideration while Updating BLS
- 26.8.6 Prevent Reading the RWW Section during Self-Programming
- 26.8.7 Setting the Boot Loader Lock Bits by SPM
- 26.8.8 EEPROM Write Prevents Writing to SPMCR
- 26.8.9 Reading the Fuse and Lock Bits from Software
- 26.8.10 Preventing Flash Corruption
- 26.8.11 Programming Time for Flash when using SPM
- 26.8.12 Simple Assembly Code Example for a Boot Loader
- 26.8.13 Boot Loader Parameters
- 26.9 Register Description
- 27. Memory Programming
- 27.1 Program And Data Memory Lock Bits
- 27.2 Fuse Bits
- 27.3 Signature Bytes
- 27.4 Calibration Byte
- 27.5 Page Size
- 27.6 Parallel Programming Parameters, Pin Mapping, and Commands
- 27.7 Parallel Programming
- 27.7.1 Enter Programming Mode
- 27.7.2 Considerations for Efficient Programming
- 27.7.3 Chip Erase
- 27.7.4 Programming the Flash
- 27.7.5 Programming the EEPROM
- 27.7.6 Reading the Flash
- 27.7.7 Reading the EEPROM
- 27.7.8 Programming the Fuse Low Bits
- 27.7.9 Programming the Fuse High Bits
- 27.7.10 Programming the Lock Bits
- 27.7.11 Reading the Fuse and Lock Bits
- 27.7.12 Reading the Signature Bytes
- 27.7.13 Reading the Calibration Byte
- 27.7.14 Parallel Programming Characteristics
- 27.8 SPI Serial Downloading
- 27.9 SPI Serial Programming Pin Mapping
- 27.10 Programming via the JTAG Interface
- 27.10.1 Programming Specific JTAG Instructions
- 27.10.2 AVR_RESET ($C)
- 27.10.3 PROG_ENABLE ($4)
- 27.10.4 PROG_COMMANDS ($5)
- 27.10.5 PROG_PAGELOAD ($6)
- 27.10.6 PROG_PAGEREAD ($7)
- 27.10.7 Data Registers
- 27.10.8 Reset Register
- 27.10.9 Programming Enable Register
- 27.10.10 Programming Command Register
- 27.10.11 Virtual Flash Page Load Register
- 27.10.12 Virtual Flash Page Read Register
- 27.10.13 Programming Algorithm
- 27.10.14 Entering Programming Mode
- 27.10.15 Leaving Programming Mode
- 27.10.16 Performing Chip Erase
- 27.10.17 Programming the Flash
- 27.10.18 Reading the Flash
- 27.10.19 Programming the EEPROM
- 27.10.20 Reading the EEPROM
- 27.10.21 Programming the Fuses
- 27.10.22 Programming the Lock Bits
- 27.10.23 Reading the Fuses and Lock Bits
- 27.10.24 Reading the Signature Bytes
- 27.10.25 Reading the Calibration Byte
- 28. Electrical Characteristics
- 29. Typical Characteristics
- 29.1 Active Supply Current
- 29.2 Idle Supply Current
- 29.3 Power-down Supply Current
- 29.4 Power-save Supply Current
- 29.5 Standby Supply Current
- 29.6 Pin Pull-up
- 29.7 Pin Driver Strength
- 29.8 Pin Thresholds and Hysteresis
- 29.9 BOD Thresholds and Analog Comparator Offset
- 29.10 Internal Oscillator Speed
- 29.11 Current Consumption of Peripheral Units
- 29.12 Current Consumption in Reset and Reset Pulsewidth
- 30. Register Summary
- 31. Instruction Set Summary
- 32. Ordering Information
- 33. Packaging Information
- 34. Errata
- 35. Datasheet Revision History
- Table of Contents
178
ATmega32A [DATASHEET]
Atmel-8155D-AVR-ATmega32A-Datasheet_02/2014
Figure 21-14. Formats and States in the Master Receiver Mode
21.7.3 Slave Receiver Mode
In the Slave Receiver mode, a number of data bytes are received from a master transmitter (see Figure 20-15). All
the status codes mentioned in this section assume that the prescaler bits are zero or are masked to zero.
$10 A repeated START condition
has been transmitted
Load SLA+R or
Load SLA+W
0
0
0
0
1
1
X
X
SLA+R will be transmitted
ACK or NOT ACK will be received
SLA+W will be transmitted
Logic will switch to masTer Transmitter mode
$38 Arbitration lost in SLA+R or NOT
ACK bit
No TWDR action or
No TWDR action
0
1
0
0
1
1
X
X
Two-wire Serial Bus will be released and not addressed
slave mode will be entered
A START condition will be transmitted when the bus
becomes free
$40 SLA+R has been transmitted;
ACK has been received
No TWDR action or
No TWDR action
0
0
0
0
1
1
0
1
Data byte will be received and NOT ACK will be
returned
Data byte will be received and ACK will be returned
$48 SLA+R has been transmitted;
NOT ACK has been received
No TWDR action or
No TWDR action or
No TWDR action
1
0
1
0
1
1
1
1
1
X
X
X
Repeated START will be transmitted
STOP condition will be transmitted and TWSTO Flag will
be reset
STOP condition followed by a START condition will be
transmitted and TWSTO Flag will be reset
$50 Data byte has been received;
ACK has been returned
Read data byte or
Read data byte
0
0
0
0
1
1
0
1
Data byte will be received and NOT ACK will be
returned
Data byte will be received and ACK will be returned
$58 Data byte has been received;
NOT ACK has been returned
Read data byte or
Read data byte or
Read data byte
1
0
1
0
1
1
1
1
1
X
X
X
Repeated START will be transmitted
STOP condition will be transmitted and TWSTO Flag will
be reset
STOP condition followed by a START condition will be
transmitted and TWSTO Flag will be reset
Table 21-3. Status Codes for Master Receiver Mode (Continued)
S SLA R A DATA A
$08
$40 $50
SLA R
$10
AP
$48
A or A
$38
Other master
continues
$38
Other master
continues
W
A
$68
Other master
continues
$78 $B0
To corresponding
states in slave mode
MR
MT
Successfull
reception
from a slave
receiver
Next transfer
started with a
repeated start
condition
Not acknowledge
received after the
slave address
Arbitration lost in slave
address or data byte
Arbitration lost and
addressed as slave
DATA A
n
From master to slave
From slave to master
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the Two-wire Serial Bus. The
prescaler bits are zero or masked to zero
PDATA A
$58
A
R
S