atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 261
atmega32u4-16mu
Manufacturer Part Number
atmega32u4-16mu
Description
Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
Manufacturer
ATMEL Corporation
Datasheet
1.ATMEGA32U4-16MU.pdf
(431 pages)
- Current page: 261 of 431
- Download datasheet (6Mb)
7766A–AVR–03/08
Figure 21-14. Data Transfer in Master Receiver Mode
A START condition is sent by writing the following value to TWCR:
TWEN must be written to one to enable the 2-wire Serial Interface, TWSTA must be written to
one to transmit a START condition and TWINT must be set to clear the TWINT Flag. The TWI
will then test the 2-wire Serial Bus and generate a START condition as soon as the bus
becomes free. After a START condition has been transmitted, the TWINT Flag is set by hard-
ware, and the status code in TWSR will be 0x08 (See
SLA+R must be transmitted. This is done by writing SLA+R to TWDR. Thereafter the TWINT bit
should be cleared (by writing it to one) to continue the transfer. This is accomplished by writing
the following value to TWCR:
When SLA+R have been transmitted and an acknowledgement bit has been received, TWINT is
set again and a number of status codes in TWSR are possible. Possible status codes in Master
mode are 0x38, 0x40, or 0x48. The appropriate action to be taken for each of these status codes
is detailed in
Flag is set high by hardware. This scheme is repeated until the last byte has been received.
After the last byte has been received, the MR should inform the ST by sending a NACK after the
last received data byte. The transfer is ended by generating a STOP condition or a repeated
START condition. A STOP condition is generated by writing the following value to TWCR:
A REPEATED START condition is generated by writing the following value to TWCR:
After a repeated START condition (state 0x10) the 2-wire Serial Interface can access the same
Slave again, or a new Slave without transmitting a STOP condition. Repeated START enables
TWCR
value
TWCR
value
TWCR
value
TWCR
value
SDA
SCL
TWINT
TWINT
TWINT
TWINT
Table
1
1
1
1
21-4. Received data can be read from the TWDR Register when the TWINT
Device 1
RECEIVER
MASTER
TWEA
TWEA
TWEA
TWEA
X
X
X
X
TRANSMITTER
TWSTA
TWSTA
TWSTA
TWSTA
Device 2
SLAVE
1
0
0
1
TWSTO
TWSTO
TWSTO
TWSTO
Device 3
0
0
1
0
........
TWWC
TWWC
TWWC
TWWC
X
X
X
X
Table
Device n
TWEN
TWEN
TWEN
TWEN
21-3). In order to enter MR mode,
V
1
1
1
1
CC
R1
ATmega32U4
–
0
–
0
–
0
–
0
R2
TWIE
TWIE
TWIE
TWIE
X
X
X
X
261
Related parts for atmega32u4-16mu
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU 2.4GHZ XCEIVER 64QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA644/AT86RF230 40-DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA644P/AT86RF230 QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA644P/AT86RF230 TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA1281/AT86RF230 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA1280/AT86RF230 100TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA1280/AT86RF100-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA2560V/AT86RF230-ZU
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA2561/AT86RF230 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU, 8BIT, AVR, 16K FLASH, 28PDIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Microcontroller Modules MCU CARD BIGAVR6 100P W/ ATMEGA2560
Manufacturer:
mikroElektronika