Datasheet

Section 7 Data Transfer Controller [H8S/2138 Group]
Rev. 4.00 Jun 06, 2006 page 169 of 1004
REJ09B0301-0400
7.3 Operation
7.3.1 Overview
When activated, the DTC reads register information that is already stored in memory and transfers
data on the basis of that register information. After the data transfer, it writes updated register
information back to memory. Pre-storage of register information in memory makes it possible to
transfer data over any required number of channels. Setting the CHNE bit to 1 makes it possible to
perform a number of transfers with a single activation.
Figure 7.2 shows a flowchart of DTC operation.
Start
Read DTC vector
Next transfer
Read register information
Data transfer
Write register information
Clear activation flag
CHNE = 1?
End
No
No
Yes
Yes
Transfer counter = 0
or DISEL = 1?
Clear DTCER
Interrupt exception
handling
Figure 7.2 Flowchart of DTC Operation