H8S2140B Datasheet, PDF (482/845 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2100 Series

Section 16 I²C Bus Interface (IIC) (Optional)
Bit Bit Name Initial Value R/W Description
1 IRIC
0
R/(W)* Clocked synchronous serial format and formatless modes:
• At the end of data transfer (rise of the 8th
transmit/receive clock with serial format selected and
rise of the 9th transmit/receive clock with formatless
selected)
• When a start condition is detected with serial format
selected
• When the SW bit in DDCSWR is set to 1
When the ICDRE or ICDRF flag is set to 1 in any operating
mode:
• When a start condition is detected in transmit mode
(when a start condition is detected in transmit mode
and the ICDRE flag is set to 1)
• When data is transferred among the ICDR register and
buffer (when data is transferred from ICDRT to ICDRS
in transmit mode and the ICDRE flag is set to 1, or
when data is transferred from ICDRS to ICDRR in
receive mode and the ICDRF flag is set to 1)
[Clearing conditions]
• When 0 is written in IRIC after reading IRIC = 1
• When ICDR is read from or written to by the DTC (This
may not function as a clearing condition depending on
the situation. For details, see the description of the DTC
operation given below.)
Note: * Only 0 can be written, to clear the flag.
When the DTC is used, IRIC is cleared automatically and transfer can be performed continuously
without CPU intervention.
When, with the I²C bus format selected, IRIC is set to 1 and an interrupt is generated, other flags
must be checked in order to identify the source that set IRIC to 1. Although each source has a
corresponding flag, caution is needed at the end of a transfer.
When the ICDRE or ICDRF flag is set, the IRTR flag may or may not be set. The IRTR flag (the
DTC start request flag) is not set at the end of a data transfer up to detection of a retransmission
start condition or stop condition after a slave address (SVA) or general call address match in I²C
bus format slave mode.
Even when the IRIC flag and IRTR flag are set, the ICDRE or ICDRF flag may not be set. The
IRIC and IRTR flags are not cleared at the end of the specified number of transfers in continuous
Rev. 3.00 Mar 21, 2006 page 428 of 788
REJ09B0300-0300