UG-1262
Rev. B | Page 233 of 312
Bits Bit
Name Settings Description
Reset Access
11 MSTOP
Stop Driven by this I
2
C Master. Asserts when this I
2
C master drives a stop condition on
the I
2
C bus. This bit, when asserted, can indicate a transaction completion, transmit
underflow, receive overflow, or a no acknowledge by the slave. This bit is different from
the TCOMP bit because this bit is not asserted when the stop condition occurs due to
any other I
2
C master. No interrupt is generated for the assertion of this bit. However, if
MCTL, Bit 8 is 1, every stop condition generates an interrupt and this bit can be read.
When this bit is read, it clears status.
0x0 RC
10 LINEBUSY
Line is Busy. Asserts when a start is detected on the I
2
C bus. Deasserts when a stop is
detected on the I
2
C bus.
0x0 R
9 MRXOVR
Master Receive FIFO Overflow. Asserts when a byte is written to the receive FIFO when
the FIFO is already full. When the bit is read, it clears the status.
0x0 RC
8 TCOMP
Transaction Complete or Stop Detected. Transaction complete. This bit asserts when a
stop condition is detected on the I
2
C bus. If MCTL, Bit 8 is 1, an interrupt is generated
when this bit asserts. This bit only asserts if the master is enabled (MCTL, Bit 0 = 1). Use
this bit to determine when it is safe to disable the master. This bit can also be used to
wait for another master transaction to complete on the I
2
C bus when this master loses
arbitration. When this bit is read, it clears status. This bit can drive an interrupt.
0x0 RC
7 NACKDATA
Acknowledge Not Received in Response to Data Write. This bit asserts when an
acknowledge is not received in response to a data write transfer. If MCTL, Bit 7 is 1, an
interrupt is generated when this bit asserts. This bit can drive an interrupt. This bit is
cleared on a read of the MSTAT register.
0x0 RC
6 MBUSY
Master Busy. This bit indicates that the master state machine is servicing a transaction.
It is cleared if the state machine is idle or another device has control of the I
2
C bus.
0x0 R
5 ALOST
Arbitration Lost. This bit asserts if the master loses arbitration. If MCLT, Bit 6 is 1, an
interrupt is generated when this bit asserts. This bit is cleared on a read of the MSTAT
register. This bit can drive an interrupt.
0x0 RC
4 NACKADDR
Acknowledge Not Received in Response to an Address. This bit asserts if an acknowledge is
not received in response to an address. If MCTL, Bit 7 is 1, an interrupt is generated
when this bit asserts. This bit is cleared on a read of the MSTAT register. This bit can
drive an interrupt.
0x0 RC
3 MRXREQ
Master Receive Request. This bit asserts when there is data in the receive FIFO. If MCTL, Bit 4
is 1, an interrupt is generated when this bit asserts. This bit can drive an interrupt.
0x0 R
2 MTXREQ
Master Transmit Request. This bit asserts when the direction bit is 0 and the transmit
FIFO is either empty or not full. If MCTL, Bit 5 is 1, an interrupt is generated when this
bit asserts. This bit can drive an interrupt.
0x0 R
[1:0]
MTXF
Master Transmit FIFO Status. Shows the master transmit FIFO status.
0x0
R
00
FIFO
empty.
10
1 byte in FIFO.
11
FIFO
full.
MASTER RECEIVE DATA REGISTER
Address: 0x40003008, Reset: 0x0000, Name: MRX
Table 285. Bit Descriptions for MRX
Bits Bit
Name Settings
Description
Reset Access
[15:8] Reserved
Reserved.
0x0 R
[7:0]
VALUE
Master Receive. Allows access to the receive data FIFO. The FIFO can hold two bytes.
0x0
R