HD6412350 Hitachi, HD6412350 Datasheet - Page 294

• Manufacturer Part Number: HD6412350
• Description: (HD6412350 / HD6432351) 16-BIT MICROCONTROLLER
• Manufacturer: Hitachi

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.
274
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
channel
DTE= 1
Yes
No
[1]
[2]
NMI Interrupt
Transfer ends
[1]
[2]
Check that DTE = 1 and
DTME = 0 in DMABCRL
Write 1 to the DTME bit.