SH7144 Datasheet, PDF (499/773 Pages) Renesas Technology Corp – Hitachi SuperH RISC engine

8. Points for Caution in Setting the Start Condition for Re-transmission
Figure 14.19 shows the timing and flowchart of the setting of the start condition for re-
transmission, and the timing with which the data is continuously written to ICDR.
IRIC=1?
No
[1]
Yes
Clear IRIC in ICSR
Set the start ^No
condition?
Yes
Read the SCL pin
No
SCL=Low?
Other processing
[2]
[1] Wait for completion of one-byte transfer.
[2] Decide whether or not SCL is low.
[3] Execuse the instruction that sets the start
Yes
Write 1 to BBSY and
0 to SCP of ICSR
condition for re-transmission.
[3]
[4] Decide whether or not SCL is high.
[5] Set the data for transmission (slave address+R/W)
Read the SCL pin
No
SCL=High?
Note: Program so that steps 3 to 5 above are
executed continuously.
[4]
Yes
Write the data for
transmission to ICDR
[5]
SCL
SDA
ACK
IRIC
bit7
Start condition
(re-transmission)
[1] Tasting of IRIC [2] Testing of SCL=Low ^{[4] Testing of SCL=high}
[3] Instruction that puts the
start condition in place
[5] Write to ICDR
Figure 14.19 Flowchart and Timing of the Execution of the Instruction that Sets the Start
Condition for Re-Transmission
Rev. 2.0, 09/02, page 459 of 732