Inter-Integrated Circuit Controller
7-73
MPU Public Peripherals
Register Access Ready (ARDY)
This bit (2) when set to 1 indicates that the previously programmed data and
command (receive or transmit, master or slave) have been performed and the
status bit has been updated. This flag is used by the local host to let it know
that the I
2
C registers are ready to be accessed again.
Table 7–56. Register Access Ready (ARDY) Set Conditions
Mode
Others
ARDY Set Conditions
Master transmit
STP = 1, RM = 0
DCOUNT=0
Master receive
STP = 1, RM = 0
DCOUNT = 0 and receiver FIFO empty
Master transmit or
receive
STP = 0, RM = 0
DCOUNT passed 0
Master transmit or
receive
RM=1
Never
Slave transmit
–
Stop condition received from master
Slave receive
–
Stop condition and receiver FIFO empty
This bit is cleared to 0 by the core with a read of the matching interrupt vector
in I2C_IV register.
-
0: No action
-
1: Access ready
Value after reset is low.
No Acknowledgment (NACK)
The no acknowledge flag bit (1) is set when the hardware detects no acknowl-
edge has been received.
This bit is cleared to 0 by the core with a read of the matching interrupt vector
in I2C_IV register.
-
0: Normal/no action required
-
1: NACK
Value after reset is low.
When a NACK occurs, the system has to perform the following actions to
recover:
1) Read the INTCODE in the I2C_IV register to release NACK in I2C_STAT.