Renesas H8S/2100 Series, Hardware Manual

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Section 18 I
2
C Bus Interface (IIC)
Rev. 1.00 Apr. 28, 2008 Page 557 of 994
REJ09B0452-0100
Bit Bit Name
Initial
Value R/W Description
5 ICDRF 0 R Receive Data Read Request Flag
Indicates the ICDR (ICDRR) status in receive mode.
0: Indicates that the data has been already read from
ICDR (ICDRR) or ICDR is initialized.
1: Indicates that data has been received successfully
and transferred from ICDRS to ICDRR, and the data
is ready to be read out.
[Setting conditions]
•
When data is received successfully and transferred
from ICDRS to ICDRR.
(1) When data is received successfully while ICDRF =
0 (at the rise of the 9th clock pulse).
(2) When ICDR is read successfully in receive mode
after data was received while ICDRF = 1.
[Clearing conditions]
•
When ICDR (ICDRR) is read.
•
When 0 is written to the ICE bit.
•
When the IIC is internally initialized using the CLR3
to CLR0 bits in DDCSWR.
When ICDRF is set due to the condition (2) above,
ICDRF is temporarily cleared to 0 when ICDR (ICDRR)
is read; however, since data is transferred from ICDRS
to ICDRR immediately, ICDRF is set to 1 again.
Note that ICDR cannot be read successfully in transmit
mode (TRS = 1) because data is not transferred from
ICDRS to ICDRR. Be sure to read data from ICDR in
receive mode (TRS = 0).