Lantronix DSTni-EX 12. Control Register, 13. Control Register Definitions, Start Condition

Models: DSTni-EX

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Control Register

Control Register

Table 3-12. Control Register

BIT

 

7

 

 

6

 

 

5

 

 

4

 

 

3

 

 

2

 

1

 

0

 

OFFSET

 

 

 

 

 

 

 

 

 

 

 

D004

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FIELD

 

IEN

 

 

ENAB

 

 

STA

 

 

STP

 

 

IFLG

 

 

AAK

 

///

 

///

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESET

 

0

 

 

0

 

 

0

 

 

0

 

0

 

0

 

0

 

0

 

RW

 

RW

 

 

RW

 

 

RW

 

 

RW

 

 

RW

 

 

RW

 

RW

 

RW

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 3-13. Control Register Definitions

 

 

 

Bits

Field Name

Description

7

IEN

Extended Slave Address

 

 

l = interrupt line (INTR) goes HIGH when the IFLG bit is set.

 

 

0 = interrupt line remains LOW (default).

6

ENAB

Extended Slave Address

 

 

1 = I2C Controller responds to calls to its slave address and to the general call

 

 

address if the GCE bit in the ADDR register is set.

 

 

0 = I2C bus inputs ISDA/ISCL are ignored and the I2C controller will not respond

 

 

to any address on the bus (default).

5

STA

Start Condition

 

 

1 = I2C controller enters master mode and transmits a START condition on the

 

 

bus when the bus is free. If the I2C controller is already in master mode and one

 

 

or more bytes have been transmitted, a repeated START condition is sent. If the

 

 

I2C controller is being accessed in slave mode, the I2C controller completes the

 

 

data transfer in slave mode and enters master mode when the bus is released.

 

 

The STA bit is cleared automatically after a START condition has been sent.

 

 

0 = no effect.

4

STP

Stop Condition

 

 

1 and I2C controller is in slave mode in master mode = a stop condition is

 

 

transmitted on the I2C bus.

 

 

0 and I2C controller is in slave mode = I2C controller behaves as if a STOP

 

 

condition has been received, but no STOP condition will be transmitted on the I2C

 

 

bus. If both STA and STP bits are set, the I2C controller transmits the STOP

 

 

condition (if in master mode), then transmits the START condition.

 

 

0 = no effect.

 

 

The STP bit is cleared automatically.

3

IFLG

I2C State

 

 

1 = an I2C state has been entered. The only state that does not set IFLG is state

 

 

F8h. See the Status register.

 

 

1 and IEN bit is set = interrupt line goes HIGH. When IFLG is set by the I2C

 

 

controller, the low period of the I2C bus clock line (SCL) is stretched and the data

 

 

transfer is suspended.

 

 

0 = interrupt line goes LOW and the I2C clock line is released.

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Page 33
Image 33
Lantronix DSTni-EX 12. Control Register, 13. Control Register Definitions, Extended Slave Address, Start Condition