RX610 Group
22. I
2
C Bus Interface (RIIC)
R01UH0032EJ0120 Rev.1.20
Page 707 of 1006
Feb 20, 2013
NALE Bit (NACK Transmission Arbitration Lost Detection Enable)
This bit is used to specify whether to cause arbitration to be lost when ACK is detected during transmission of NACK in
receive mode (such as when slaves with the same address exist on the bus or when two or more masters select the same
slave device simultaneously with different number of receive bytes).
SALE Bit (Slave Arbitration Lost Detection Enable)
This bit is used to specify whether to cause arbitration to be lost when a value different from the value being transmitted
is detected on the bus in slave transmit mode (such as when slaves with the same address exist on the bus or when a
mismatch with the transmit data occurs due to noise).
NACKE Bit (NACK Reception Transfer Suspension Enable)
This bit is used to specify whether to continue or discontinue the transfer operation when NACK is received from the
slave device in transmit mode. Normally, set this bit to 1.
When NACK is received with the NACKE bit set to 1, the next transfer operation is suspended.
When the NACKE bit is 0, the next transfer operation is continued regardless of the received acknowledge content.
For details on the NACK reception transfer suspension function, see section 22.8.2, NACK Reception Transfer
Suspension Function
NFE Bit (Digital Noise Filter Circuit Enable)
This bit is used to specify whether to use a digital noise filter circuit.
SCLE Bit (SCL Synchronous Circuit Enable)
This bit is used to specify whether to synchronize the SCL clock with the SCL input clock. Normally, set this bit to 1.
When the SCLE bit is cleared to 0 (SCL synchronous circuit is invalid), the RIIC does not synchronize the SCL clock
with the SCL input clock (by detecting the SCLn line level) for the SCL clock output operation in master mode, and the
RIIC outputs the SCL clock with the transfer rate set in ICBRH and ICBRL regardless of the SCLn line state. For this
reason, if the bus load of the I
2
C bus line is much larger than the specification value or if the SCL clock output overlaps
in multiple masters, the short-cycle SCL clock that does not meet the specification may be output. When SCL
synchronous circuit is invalid, it also affects the issuance of a start condition, restart condition, and stop condition, and
the continuous output of extra SCL clock cycles.
This bit must not be cleared to 0 except for checking the output of the transfer rate that was set during debugging.
FMPE Bit (Fast-mode Plus Enable)
This bit is used to specify whether to use a slope control circuit for Fast-mode Plus[fm+].
When this bit is set to 1, a slope control circuit conforming to the Fast-mode Plus[fm+] slope control standard (tof) of the
I
2
C bus is selected. When this bit is cleared to 0, a slope control circuit conforming to the Standard-mode[Sm] and
Fast-mode[fm] slope control standard (tof) of the I
2
C bus is selected.
Set this bit to 1 when using the transmission rate within a range up to 1 Mbps (Fast-mode Plus[fm+]) of the I
2
C bus
standard. Clear this bit to 0 when using the transmission rate at other rates (up to 100 kbps[Sm], up to 400 kbps[fm]) or
for SMBus (10 to 100 kbps).