Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Fiche De Données

Codes de produits
AT91SAM9N12-EK
Page de 1104
735
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
39.12.1 TWI Control Register
Name: 
TWI_CR
Addresses:
0xF8010000 (0), 0xF8014000 (1)
Access: Write-only
Reset: 0x00000000
• START: Send a START Condition
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).
• STOP: Send a STOP Condition
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.
• MSEN: TWI Master Mode Enabled
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.
• MSDIS:  TWI  Master Mode Disabled
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.
• SVEN: TWI Slave Mode Enabled
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.
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SWRST
QUICK
SVDIS
SVEN
MSDIS
MSEN
STOP
START