RX610 Group
22. I
2
C Bus Interface (RIIC)
R01UH0032EJ0120 Rev.1.20
Page 695 of 1006
Feb 20, 2013
22.2.2
I
2
C Bus Control Register 2 (ICCR2)
b7
b6
b5
b4
b3
b2
b1
b0
Value after reset:
0
0
0
0
0
0
0
0
BBSY
MST
TRS
—
SP
RS
ST
—
Addresses: RIIC0.ICCR2 0008 8301h, RIIC1.ICCR2 0008 8321h
Bit
Symbol
Bit Name
Description
R/W
b0
Reserved
This bit is always read as 0. The write value should always be 0.
R/W
b1
ST
Start Condition Issuance Request
0: Does not request to issue a start condition
1: Requests to issue a start condition
R/W
b2
RS
Restart Condition Issuance Request
0: Does not request to issue a restart condition
1: Requests to issue a restart condition
R/W
b3
SP
Stop Condition Issuance Request
0: Does not request to issue a stop condition
1: Requests to issue a stop condition
R/W
b4
Reserved
This bit is always read as 0. The write value should always be 0.
R/W
b5
TRS
Transmit/Receive Mode
0: Receive mode
1: Transmit mode
R/W
*
b6
MST
Master/Slave Mode
0: Slave mode
1: Transmit mode
R/W
*
b7
BBSY
Bus Busy Detection Flag
0: The I
2
C bus is released (bus free state)
1: The I
2
C bus is occupied (bus busy state or in the bus free state)
R
Note:
*
When the MTWP bit in ICMR1 is set to 1, the MST and TRS bits can be written to.
ICCR2 has a flag function that indicates whether or not the I
2
C bus is occupied and whether the RIIC is in
transmit/receive or master/slave mode as well as a function to issue a start or stop condition.
ST Bit (Start Condition Issuance Request)
This bit is used to request transition to master mode and issuance of a start condition.
When this bit is set to 1 to request to issue a start condition, a start condition is issued when the BBSY flag is set to 0
(bus free).
For details on the start condition issuance, see section 22.10, Start Condition/Restart Condition/Stop Condition Issuing
Function.
[Setting condition]
•
When 1 is written to the ST bit
[Clearing conditions]
•
When 0 is written to the ST bit
•
When a start condition has been issued
•
When the AL (arbitration lost) flag in ICSR2 is set to 1
•
When 1 is written to the IICRST bit in ICCR1 to apply an RIIC reset or an internal reset
Note: Set the ST bit to 1 (start condition issuance request) when the BBSY flag is set to 0 (bus free).
Note that arbitration may be lost if the ST bit is set to 1 (start condition issuance request) when the BBSY flag is
set to 1 (bus busy).