HD6417641 RENESAS [Renesas Technology Corp], HD6417641 Datasheet - Page 468

• Manufacturer Part Number: HD6417641
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 13 Direct Memory Access Controller (DMAC)
Note:
If DMA transfers are requested to multiple channels simultaneously, the DMAC performs
transfers according to the specified channel priority. The channel priority is determined by the
round-robin select bits (RC0, RC1, RC2, RC3) and priority mode bits (PR1 and PR0) of the
DMAOR register.
Rev. 4.00 Sep. 14, 2005 Page 418 of 982
REJ09B0023-0400
Bit
16
15 to 6
5
4
3
2
1, 0
*
Bit Name
DME

RC0
RC1
RC2
RC3

Writing 0 is possible to clear the flag.
Initial
Value
0
All 0
0
0
0
0
All 0
R/W
R
R/W
R/W
R/W
R/W
R
R/W
Description
DMA Master Enable
DME enables or disables DMA transfers on all
channels. If the DME bit and the DE bit corresponding
to each channel in CHCR are set to 1s, transfer is
enabled in the corresponding channel. If this bit is
cleared during transfer, transfers in all the channels
can be terminated.
Even if the DME bit is set, transfer is not enabled if the
TE bit is 1 or the DE bit is 0 in CHCR, or the NMIF bit
is 1 in DMAOR.
0: Disable DMA transfers on all channels
1: Enable DMA transfers on all channels
Reserved
These bits are always read as 0. The write value
should always be 0.
Round Robin Cannel Select
RC3, RC2, RC1, and RC0 select the priority level
between channels when there are transfer requests for
multiple channels simultaneously.
0: The priority level of the CHn (n: 0 to 3) is fixed.
1: The priority level of the CHn (n: 0 to 3) is determined
Reserved
These bits are always read as 0. The write value
should always be 0.
When all RC bits is 0, the priority level is:
CH0 > CH1 > CH2 > CH3, equals with fixed mode
(mdoe7).
by the round-robin. When all RC bits are 1, the
priority level between channels equals with round-
robin mode (mode 5).