H8S-2128 Datasheet, PDF (476/843 Pages) Renesas Technology Corp – Single-Chip Microcomputer

16.3.6 IRIC Setting Timing and SCL Control
The interrupt request flag (IRIC) is set at different times depending on the WAIT bit in ICMR, the
FS bit in SAR, and the FSX bit in SARX. If the TDRE or RDRF internal flag is set to 1, SCL is
automatically held low after one frame has been transferred; this timing is synchronized with the
internal clock. Figure 16.12 shows the IRIC set timing and SCL control.
(a) When WAIT = 0, and FS = 0 or FSX = 0 (I²C bus format, no wait)
SCL
7
8
9
1
SDA
7
8
A
1
IRIC
User processing
Clear IRIC
Write to ICDR (transmit)
or read ICDR (receive)
(b) When WAIT = 1, and FS = 0 or FSX = 0 (I²C bus format, wait inserted)
SCL
8
9
1
SDA
8
A
1
IRIC
User processing
Clear
IRIC
Clear Write to ICDR (transmit)
IRIC or read ICDR (receive)
(c) When FS = 1 and FSX = 1 (synchronous serial format)
SCL
7
8
1
SDA
7
8
1
IRIC
User processing
Clear IRIC
Write to ICDR (transmit)
or read ICDR (receive)
Figure 16.12 IRIC Setting Timing and SCL Control
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