Datasheet

Section 18 I
2
C Bus Interface (IIC)
Rev. 2.00 Aug. 20, 2008 Page 658 of 1198
REJ09B0403-0200
8. Notes on start condition issuance for retransmission
Figure 18.30 shows the timing of start condition issuance for retransmission, and the timing for
subsequently writing data to ICDR, together with the corresponding flowchart. Write the
transmit data to ICDR after the start condition for retransmission is issued and then the start
condition is actually generated.
SDA
IRIC
SCL
ACK
Bit 7
[3] (Retransmission) Start condition instruction issuance
[4] IRIC determination
[5] ICDR write (transmit data)
[2] Determination of SCL = Low
[1] IRIC determination
Start condition generation
(retransmission)
IRIC = 1?
Yes
Clear IRIC in ICCR
Read SCL pin
Write transmit data to ICDR
Set BBSY = 1,
SCP = 0 (ICCR)
[1]
[1] Wait for end of 1-byte transfer
[2] Determine whether SCL is low
[3] Issue start condition instruction for retransmission
[4] Determine whether start condition is generated or not
[5] Set transmit data (slave address + R/W)
[2]
[3]
[4]
[5]
Yes
No
No
IRIC = 1?
Yes
SCL = Low?
No
Note: Program so that processing from [3] to [5]
is executed continuously.
9
Figure 18.30 Flowchart for Start Condition Issuance Instruction
for Retransmission and Timing
Note: This restriction on usage can be canceled by setting the FNC1 and FNC0 bits to B'11 in
ICXR.