HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 331

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

7.5.15
When an NMI interrupt is requested, burst mode transfer in full address mode is interrupted. An
NMI interrupt does not affect the operation of the DMAC in other modes.
In full address mode, transfer is enabled for a channel when both the DTE bit and the DTME bit
are set to 1. With burst mode setting, the DTME bit is cleared when an NMI interrupt is requested.
If the DTME bit is cleared during burst mode transfer, the DMAC discontinues transfer on
completion of the 1-byte or 1-word transfer in progress, then releases the bus, which passes to the
CPU.
The channel on which transfer was interrupted can be restarted by setting the DTME bit to 1 again.
Figure 7.36 shows the procedure for continuing transfer when it has been interrupted by an NMI
interrupt on a channel designated for burst mode transfer.
Figure 7.36 Example of Procedure for Continuing Transfer on Channel Interrupted by
transfer on interrupted
NMI Interrupts and DMAC
Transfer continues
Set DTME bit to 1
Resumption of
DTME = 0
DTE = 1
channel
Yes
No
[1]
[2]
Section 7 DMA Controller (Not Supported in the H8S/2321)
NMI Interrupt
Transfer ends
Rev.6.00 Sep. 27, 2007 Page 301 of 1268
[1]
[2]
Check that DTE = 1 and
DTME = 0 in DMABCRL.
Write 1 to the DTME bit.
REJ09B0220-0600