ATmega16A Atmel Corporation, ATmega16A Datasheet - Page 188

• Manufacturer Part Number: ATmega16A
• Manufacturer: Atmel Corporation

Specifications of ATmega16A

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Table 20-2.
188
Status Code
(TWSR)
Prescaler Bits
are 0
$08
$10
$18
$20
$28
$30
$38
ATmega16A
Status of the Two-wire Serial
Bus and Two-wire Serial Inter-
face Hardware
A START condition has been
transmitted
A repeated START condition
has been transmitted
SLA+W has been transmitted;
ACK has been received
SLA+W has been transmitted;
NOT ACK has been received
Data byte has been transmitted;
ACK has been received
Data byte has been transmitted;
NOT ACK has been received
Arbitration lost in SLA+W or data
bytes
Status Codes for Master Transmitter Mode
After a repeated START condition (state $10) the Two-wire Serial Interface can access the
same Slave again, or a new Slave without transmitting a STOP condition. Repeated START
enables the Master to switch between Slaves, Master Transmitter mode and Master Receiver
mode without losing control of the bus.
To/from TWDR
Load SLA+W
Load SLA+W or
Load SLA+R
Load data byte or
No TWDR action or
No TWDR action or
No TWDR action
Load data byte or
No TWDR action or
No TWDR action or
No TWDR action
Load data byte or
No TWDR action or
No TWDR action or
No TWDR action
Load data byte or
No TWDR action or
No TWDR action or
No TWDR action
No TWDR action or
No TWDR action
Application Software Response
STA
0
0
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
STO
0
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
To TWCR
TWINT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
TWEA
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Next Action Taken by TWI Hardware
SLA+W will be transmitted;
ACK or NOT ACK will be received
SLA+W will be transmitted;
ACK or NOT ACK will be received
SLA+R will be transmitted;
Logic will switch to Master Receiver mode
Data byte will be transmitted and ACK or NOT ACK will
be received
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
Data byte will be transmitted and ACK or NOT ACK will
be received
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
Data byte will be transmitted and ACK or NOT ACK will
be received
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
Data byte will be transmitted and ACK or NOT ACK will
be received
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
Two-wire Serial Bus will be released and not addressed
Slave mode entered
A START condition will be transmitted when the bus be-
comes free
8154B–AVR–07/09