ATMEGA32HVB-8X3 Atmel, ATMEGA32HVB-8X3 Datasheet - Page 175

• Manufacturer Part Number: ATMEGA32HVB-8X3
• Description: MCU AVR 32KB FLASH 8MHZ 44TSSOP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32HVB-8X3

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SPI
• Peripherals: POR, WDT
• Number Of I /o: 17
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 25 V
• Data Converters: A/D 7x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TSSOP
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI, TWI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 17
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRSB200
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 7 Channel
• Package: 44TSSOP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 8 MHz
• Operating Supply Voltage: 5|9|12|15|18|24 V
• For Use With: ATSTK524 - KIT STARTER ATMEGA32M1/MEGA32C1ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8042B–AVR–06/10
The upper seven bits are the address to which the Two-wire Serial Interface will respond when
addressed by a master. If the LSB is set, the TWI will respond to the general call address (0x00),
otherwise it will ignore the general call address.
TWEN must be written to one to enable the TWI. The TWEA bit must be written to one to enable
the acknowledgment of the device’s own slave address or the general call address. TWSTA and
TWSTO must be written to zero.
When TWAR and TWCR have been initialized, the TWI waits until it is addressed by its own
slave address (or the general call address if enabled) followed by the data direction bit. If the
direction bit is “0” (write), the TWI will operate in SR mode, otherwise ST mode is entered. After
its own slave address and the write bit have been received, the TWINT flag is set and a valid
status code can be read from TWSR. The status code is used to determine the appropriate soft-
ware action. The appropriate action to be taken for each status code is detailed in
The Slave Receiver mode may also be entered if arbitration is lost while the TWI is in the Master
mode (see states 0x68 and 0x78).
If the TWEA bit is reset during a transfer, the TWI will return a “Not Acknowledge” (“1”) to SDA
after the next received data byte. This can be used to indicate that the slave is not able to
receive any more bytes. While TWEA is zero, the TWI does not acknowledge its own slave
address. However, the Two-wire Serial Bus is still monitored and address recognition may
resume at any time by setting TWEA. This implies that the TWEA bit may be used to temporarily
isolate the TWI from the Two-wire Serial Bus.
In all sleep modes other than Idle mode, the clock system to the TWI is turned off. If the TWEA
bit is set, the interface can still acknowledge its own slave address or the general call address by
using the Two-wire Serial Bus clock as a clock source. The part will then wake-up from sleep
and the TWI will hold the SCL clock low during the wake up and until the TWINT flag is cleared
(by writing it to one). Further data reception will be carried out as normal, with the AVR clocks
running as normal. Observe that if the AVR is set up with a long start-up time, the SCL line may
be held low for a long time, blocking other data transmissions.
Note that the Two-wire Serial Interface Data Register – TWDR does not reflect the last byte
present on the bus when waking up from these Sleep modes.
TWAR
Value
TWCR
Value
TWINT
TWA6
0
TWEA
TWA5
1
TWSTA
TWA4
0
Device’s Own Slave Address
TWSTO
TWA3
0
ATmega16HVB/32HVB
TWWC
TWA2
0
TWEN
TWA1
1
TWA0
–
0
Table
TWGCE
TWIE
X
27-4.
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