Renesas H8S/2111B - Manual (Page 377)

Rev. 1.00, 05/04, page 343 of 544
10. Note on IRIC flag clear when the wait function is used
If the rise time of SCL exceeds the stipulated value or a slave device in which a wait can be
inserted by driving the SCL pin low is used when the wait function is used in I
2 C bust interface
master mode, the IRIC flag should be cleared after determining that the SCL is low, as
described below.
If the IRIC flag is cleared to 0 when WAIT = 1 while the SCL is extending the high level time,
the SDA level may change before the SCL goes low, which may generate a start or stop
condition erroneously.
SCL
IRIC
[1] SCL = low determination
VIH
[2] IRIC clear
SDA
Secures a high period
SCL = low detected
Figure 13.32 IRIC Flag Clearing Timing when WAIT = 1
Note: This restriction on usage can be canceled by setting the FNC1 and FNC0 bits to 1 in
ICXR.