Register 2: I
2
C Master Control/Status (I2CMCS), offset 0x004
This register accesses status bits when read and control bits when written. When read, the status
register indicates the state of the I
2
C bus controller. When written, the control register configures
the I
2
C controller operation.
The START bit generates the START or REPEATED START condition. The STOP bit determines if
the cycle stops at the end of the data cycle or continues on to a repeated START condition. To
generate a single transmit cycle, the I
2
C Master Slave Address (I2CMSA) register is written with
the desired address, the R/S bit is cleared, and this register is written with ACK=X (0 or 1), STOP=1,
START=1, and RUN=1 to perform the operation and stop. When the operation is completed (or
aborted due an error), an interrupt becomes active and the data may be read from the I2CMDR
register. When the I
2
C module operates in Master receiver mode, the ACK bit is normally set, causing
the I
2
C bus controller to transmit an acknowledge automatically after each byte. This bit must be
cleared when the I
2
C bus controller requires no further data to be transmitted from the slave
transmitter.
Read-Only Status Register
I2C Master Control/Status (I2CMCS)
I2C 0 base: 0x4002.0000
I2C 1 base: 0x4002.1000
Offset 0x004
Type RO, reset 0x0000.0020
16171819202122232425262728293031
reserved
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
BUSYERRORADRACKDATACKARBLSTIDLEBUSBSYreserved
ROROROROROROROROROROROROROROROROType
0000010000000000Reset
DescriptionResetTypeNameBit/Field
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x0000.00ROreserved31:7
Bus Busy
DescriptionValue
The I
2
C bus is idle.0
The I
2
C bus is busy.1
The bit changes based on the START and STOP conditions.
0ROBUSBSY6
I
2
C Idle
DescriptionValue
The I
2
C controller is not idle.0
The I
2
C controller is idle.1
1ROIDLE5
737July 24, 2012
Texas Instruments-Production Data
Stellaris
®
LM3S6G65 Microcontroller
OBSOLETE: TI has discontinued production of this device.