Datasheet
Section 18 I
2
C Bus Interface [Option]
(This function is not available in the H8S/2695)
R01UH0166EJ0600 Rev. 6.00 Page 887 of 1434
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
18.3.8 Operation Using the DTC
*
The I
2
C bus format provides for selection of the slave device and transfer direction by means of
the slave address and the R/W bit, confirmation of reception with the acknowledge bit, indication
of the last frame, and so on. Therefore, continuous data transfer using the DTC
*
must be carried
out in conjunction with CPU processing by means of interrupts.
Table 18.5 shows some examples of processing using the DTC
*
. These examples assume that the
number of transfer data bytes is known in slave mode.
Note: * The DTC function is not available in the H8S/2695.
Table 18.5 Examples of Operation Using the DTC
*
Item
Master Transmit
Mode
Master Receive
Mode
Slave Transmit
Mode
Slave Receive
Mode
Slave address +
R/W bit
transmission/
reception
Transmission by
DTC
*
(ICDR write)
Transmission by
CPU (ICDR write)
Reception by
CPU (ICDR read)
Reception by CPU
(ICDR read)
Dummy data
read
— Processing by
CPU (ICDR read)
— —
Actual data
transmission/
reception
Transmission by
DTC
*
(ICDR write)
Reception by
DTC
*
(ICDR read)
Transmission by
DTC
*
(ICDR write)
Reception by DTC
*
(ICDR read)
Dummy data
(H'FF) write
— — Processing by
DTC
*
(ICDR write)
—
Last frame
processing
Not necessary Reception by
CPU (ICDR read)
Not necessary Reception by CPU
(ICDR read)
Transfer request
processing after
last frame
processing
1st time: Clearing
by CPU
2nd time: End
condition issuance
by CPU
Not necessary Automatic clearing
on detection of end
condition during
transmission of
dummy data (H'FF)
Not necessary
Setting of
number of DTC
*
transfer data
frames
Transmission:
Actual data count
+ 1 (+1 equivalent
to slave address +
R/W bits)
Reception: Actual
data count
Transmission:
Actual data count
+ 1 (+1 equivalent
to dummy data
(H'FF))
Reception: Actual
data count
Note: * The DTC function is not available in the H8S/2695.