Operation; Figure 7.4 Dtc Operation Flowchart - Renesas H8S/2158 User Manual

Section 7 Data Transfer Controller (DTC)
7.5

Operation

The DTC stores register information in on-chip RAM. When activated, the DTC reads register
information in on-chip RAM and transfers data. After the data transfer, the DTC writes updated
register information back to on-chip RAM. The pre-storage of register information in memory
makes it possible to transfer data over any required number of channels. The transfer mode can be
specified as normal, repeat, or block transfer mode. Setting the CHNE bit in MRB to 1 makes it
possible to perform a number of transfers with a single activation source (chain transfer).
The 24-bit SAR designates the DTC transfer source address, and the 24-bit DAR designates the
transfer destination address. After each transfer, SAR and DAR are independently incremented,
decremented, or left fixed depending on its register information.
Rev. 3.00 Jan 25, 2006 page 156 of 872
REJ09B0286-0300
Start
Read DTC vector
Read register information
Data transfer
Write register information
CHNE = 1
Yes
No
Transfer counter = 0
Yes
or DISEL = 1
No
Clear an activation flag
End

Figure 7.4 DTC Operation Flowchart

Next transfer
Clear DTCER
Interrupt exception
handling