18.12 Start Condition/Restart Condition/Stop Condition Issuing Function; Issuing A Start Condition; Issuing A Restart Condition - Renesas RZ/A Series User Manual

RZ/A1L Group, RZ/A1LU Group, RZ/A1LC Group

18.12 Start Condition/Restart Condition/Stop Condition Issuing Function

18.12.1

Issuing a Start Condition

The RIIC issues a start condition when the RIICnCR2.ST bit is set to 1.
When the ST bit is set to 1, a start condition issuance request is made and the RIIC issues a start
condition when the RIICnCR2.BBSY flag is 0 (bus free). When a start condition is issued normally, the
RIIC automatically shifts to the master transmit mode.
A start condition is issued in the following sequence.
[Start condition issuance]
• Drive the SDA line low (high level to low level).
• Ensure the time set in RIICnBRH and the start condition hold time.
• Drive the SCL line low (high level to low level).
• Detect low level of the SCL line and ensure the low-level period of SCL line set in RIICnBRL.
18.12.2

Issuing a Restart Condition

The RIIC issues a restart condition when the RIICnCR2.RS bit is set to 1.
When the RS bit is set to 1, a restart condition issuance request is made and the RIIC issues a restart
condition when the RIICnCR2.BBSY flag is 1 (bus busy) and the RIICnCR2.MST bit is 1 (master
mode).
A restart condition is issued in the following sequence.
[Restart condition issuance]
• Release the SDA line.
• Ensure the low-level period of SCL line set in RIICnBRL.
• Release the SCL line (low level to high level).
• Detect a high level of the SCL line and ensure the time set in RIICnBRL and the restart condition
setup time.
• Drive the SDA line low (high level to low level).
• Ensure the time set in RIICnBRH and the restart condition hold time.
• Drive the SCL line low (high level to low level).
• Detect a low level of the SCL line and ensure the low-level period of SCL line set in RIICnBRL.
R01UH0437EJ0600 Rev.6.00
Jan 29, 2021
18. I²C Bus Interface
18-81