Rev. 1.0, 02/00, page 473 of 1141
23.2.5
I
2
C Bus Control Register (ICCR)
7
ICE
0
R/W
6
IEIC
0
R/W
5
MST
0
R/W
4
TRS
0
R/W
3
ACKE
0
R/W
0
SCP
1
W
2
BBSY
0
R/W
1
IRIC
0
R/(W)*
Note: * Only 0 can be written to clear the flag.
Bit :
Initial value :
R/W :
ICCR is an 8-bit readable/writable register that enables or disables the I
2
C bus interface, enables or
disables interrupts, selects master or slave mode and transmission or reception, enables or disables
acknowledgement, confirms the I
2
C bus interface bus status, issues start/stop conditions, and
performs interrupt flag confirmation.
ICCR is initialized to H'01 by a reset.
Bit 7
I
2
C Bus Interface Enable (ICE): Selects whether or not the I
2
C bus interface is to be
used. When ICE is set to 1, port pins function as SCL and SDA input/output pins and transfer
operations are enabled. When ICE is cleared to 0, the IIC stops and its internal status is initialized.
The SAR and SARX registers can be accessed when ICE is 0. The ICMR and ICDR registers can
be accessed when ICE is 1.
Bit 7
ICE
Description
0
I
2
C bus interface module disabled, with SCL and SDA signal pins set to port function
The internal status of the IIC is initialized
SAR and SARX can be accessed
(Initial value)
1
I
2
C bus interface module enabled for transfer operations (pins SCL and SCA are
driving the bus)
ICMR and ICDR can be accessed
Bit 6
I
2
C Bus Interface Interrupt Enable (IEIC): Enables or disables interrupts from the I
2
C
bus interface to the CPU.
Bit 6
IEIC
Description
0
Interrupts disabled
(Initial value)
1
Interrupts enabled