RX610 Group
22. I
2
C Bus Interface (RIIC)
R01UH0032EJ0120 Rev.1.20
Page 722 of 1006
Feb 20, 2013
22.2.13 I
2
C Bus Bit Rate Low-Level Register (ICBRL)
Addresses: RIIC0.ICBRH 0008 8310h, RIIC1.ICBRH 0008 8330h
b7
b6
b5
b4
b3
b2
b1
b0
Value after reset:
1
1
1
1
1
1
1
1
—
—
—
BRL[4:0]
Bit
Symbol
Bit Name
Description
R/W
b4 to b0
BRL[4:0]
Bit Rate Low-Level Period
Low-level period of SCL clock
R/W
b7 to b5
Reserved
These bits are always read as 1. The write value should always
be 1.
R/W
ICBRL is a 5-bit register to set the low-level period of SCL clock. It also works to generate the data setup time for
automatic SCL low-hold operation (see section 22.8, Function to Automatically Hold SCLn Clock Low); when the RIIC
is used only in slave mode, this register needs to be set to a value longer than the data setup time*.
ICBRL counts the low-level period with the internal reference clock source (IIC
φ
) specified by the CKS[2:0] bits in
ICMR1.
Note: Data setup time (tSU: DAT)
250 ns (up to 100 kbps: standard mode [Sm])
100 ns (up to 400 kbps: fast mode [fm])
50 ns (up to 1 Mbps: fast mode plus [fm+])