h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 569

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

SDA
SCL
TRS
Notes on ICDR Reads and ICCR Access in Slave Transmit Mode
In a transmit operation in the slave mode of the I
or read or write to the ICCR register during the period indicated by the shaded portion in figure
16.22.
Normally, when interrupt processing is triggered in synchronization with the rising edge of the
9th clock cycle, the period in question has already elapsed when the transition to interrupt
processing takes place, so there is no problem with reading the ICDR register or reading or
writing to the ICCR register.
To ensure that the interrupt processing is performed properly, one of the following two
conditions should be applied.
(1) Make sure that reading received data from the ICDR register, or reading or writing to the
(2) Monitor the BC2 to BC0 counter in the ICMR register and, when the value of BC2 to BC0
ICCR register, is completed before the next slave address receive operation starts.
is 000 (8th or 9th clock cycle), allow a waiting time of at least 2 transfer clock cycles in
order to involve the problem period in question before reading from the ICDR register, or
reading or writing to the ICCR register.
Figure 16.22 ICDR Read and ICCR Access Timing in Slave Transmit Mode
Address received
R/W
8
Detection of 9th clock
cycle rising edge
A
9
Period when ICDR reads and ICCR
reads and writes are prohibited
(6 system clock cycles)
Section 16 I
Waveforms if
problem occurs
2
C bus interface, do not read the ICDR register
Rev. 4.00 Jun 06, 2006 page 515 of 1004
2
C Bus Interface [H8S/2138 Group Option]
Data transmission
REJ09B0301-0400
Bit 7
ICDR write