Datasheet

Section 18 I
2
C Bus Interface [Option]
(This function is not available in the H8S/2695)
Page 886 of 1434 R01UH0166EJ0600 Rev. 6.00
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
18.3.7 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 18.19 shows the IRIC set timing and SCL control.
(a) When WAIT = 0, and FS = 0 or FSX = 0 (I
2
C bus format, no wait)
SCL
SDA
IRIC
User processing Clear IRIC Write to ICDR (transmit)
or read ICDR (receive)
1A8
1
1
A
7
1897
(b) When WAIT = 1, and FS = 0 or FSX = 0 (I
2
C bus format, wait inserted)
SCL
SDA
IRIC
User processing Clear
IRIC
Clear
IRIC
Write to ICDR (transmit)
or read ICDR (receive)
SCL
SDA
IRIC
User processing
(c) When FS = 1 and FSX = 1 (synchronous serial format)
Clear IRIC Write to ICDR (transmit)
or read ICDR (receive)
8
89
8
7
1
8
7
1
Figure 18.19 IRIC Setting Timing and SCL Control