Nxp Semiconductors UM10237 用户手册

UM10237_2

© NXP B.V. 2008. All rights reserved.

The I2C_CTL register is used to enable interrupts and reset the I

2

C state machine. 

Enabled interrupts cause the USB_I2C_INT interrupt output line to be asserted when set.

 

8

RFF

Receive FIFO Full (RFF). This bit is set when the RX FIFO is full 
and cannot accept any more data. It is cleared when the RX 
FIFO is not full. If a byte arrives when the Receive FIFO is full, 
the SCL is held low until the CPU reads the RX FIFO and makes 
room for it.

0

0

RX FIFO is not full

1

RX FIFO is full

9

RFE

Receive FIFO Empty. RFE is set when the RX FIFO is empty 
and is cleared when the RX FIFO contains valid data.

1

0

RX FIFO contains data.

1

RX FIFO is empty

10

TFF

Transmit FIFO Full. TFF is set when the TX FIFO is full and is 
cleared when the TX FIFO is not full.

0

0

TX FIFO is not full.

1

TX  FIFO  is  full

11

TFE

Transmit FIFO Empty. TFE is set when the TX FIFO is empty 
and is cleared when the TX FIFO contains valid data.

1

0

TX FIFO contains valid data.

1

TX  FIFO  is  empty

31:12 -

NA

Reserved, user software should not write ones to reserved bits. 
The value read from a reserved bit is not defined.

NA

0

TDIE

Transmit Done Interrupt Enable. This enables the TDI interrupt signalling that this I

2

C 

issued a STOP condition.

0

0

Disable the TDI interrupt.

1

Enable the TDI interrupt.

1

AFIE

Transmitter Arbitration Failure Interrupt Enable. This enables the AFI interrupt which is 
asserted during transmission when trying to set SDA high, but the bus is driven low by 
another device.

0

0

Disable the AFI.

1

Enable the AFI.

2

NAIE

Transmitter No Acknowledge Interrupt Enable. This enables the NAI interrupt signalling 
that transmitted byte was not acknowledged.

0

0

Disable the NAI.

1

Enable the NAI.