HD64F3664BPV Datasheet, PDF (290/446 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 15 I²C Bus Interface (IIC)
15.4.7 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 15.11 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 15.11 IRIC Setting Timing and SCL Control
Rev. 6.00 Mar. 24, 2006 Page 260 of 412
REJ09B0142-0600