Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos

 657

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

Name: TWI_CR

0x40018000 (0), 0x4001C000 (1)

Access: Write-only

Reset: 0x00000000

0 = No effect.

1 = A frame beginning with a START bit is transmitted according to the features defined in the mode register.

This action is necessary when the TWI peripheral wants to read data from a slave. When configured in Master Mode with a write 
operation, a frame is sent as soon as the user writes a character in the Transmit Holding Register (TWI_THR).

0 = No effect.

1 = STOP Condition is sent just after completing the current byte transmission in master read mode.

– In single data byte master read, the START and STOP must both be set.

– In multiple data bytes master read, the STOP must be set after the last data received but one.

– In master read mode, if a NACK bit is received, the STOP is automatically performed.

– In master data write operation, a STOP condition will be sent after the transmission of the current data is

finished.

0 = No effect.

1 = If MSDIS = 0, the master mode is enabled. 

Note:

Switching from Slave to Master mode is only permitted when TXCOMP = 1.

0 = No effect.

1 = The master mode is disabled, all pending data is transmitted. The shifter and holding characters (if it contains data) are trans-
mitted in case of write operation. In read operation, the character being transferred must be completely received before disabling.

0 = No effect.

1 = If SVDIS = 0, the slave mode is enabled.

Note:

Switching from Master to Slave mode is only permitted when TXCOMP = 1.

31

30

29

28

27

26

25

24

–

–

–

–

–

–

–

–

23

22

21

20

19

18

17

16

–

–

–

–

–

–

–

–

15

14

13

12

11

10

9

8

–

–

–

–

–

–

–

–

7

6

5

4

3

2

1

0

SWRST

QUICK

SVDIS

SVEN

MSDIS

MSEN

STOP

START