HD6432670 Hitachi, HD6432670 Datasheet - Page 398

• Manufacturer Part Number: HD6432670
• Description: (HD64F267x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

8.4.5
There are two transfer modes: normal transfer mode and block transfer mode. When the activation
source is an external request, either normal transfer mode or block transfer mode can be selected.
When the activation source is an auto request, normal transfer mode is used.
Normal Transfer Mode: In normal transfer mode, transfer of one transfer unit is processed in
response to one transfer request. EDTCR functions as a 24-bit transfer counter.
The
time a transfer request is accepted and transfer processing is started.
Figure 8.7 shows examples of DMA transfer timing in normal transfer mode.
Rev. 2.0, 04/02, page 352 of 906
Bus cycle
Bus cycle
Transfer conditions:
Transfer conditions:
Auto request mode, BGUP = 0
Auto request mode, BGUP = 1
Transfer Modes
signal is output only for the last DMA transfer. The
CPU
CPU
Figure 8.6 Examples of Timing in Burst Mode
EXDMAC
CPU
EXDMAC
EXDMAC operates alternately with CPU
CPU
EXDMAC
EXDMAC
CPU cycle not generated
EXDMAC
CPU
EXDMAC
signal is output each
CPU
CPU
CPU