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5 dma operation register (dmaor) – Renesas SH7641 User Manual

Page 466

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Section 13 Direct Memory Access Controller (DMAC)

Rev. 4.00 Sep. 14, 2005 Page 416 of 982

REJ09B0023-0400

13.3.5

DMA Operation Register (DMAOR)

The DMA operation register (DMAOR) is a 32-bit read/write register that specifies the priority
level of channels at the DMA transfer. This register shows the DMA transfer status. The DMAOR
is initialized to H'00000000 at reset and retains the current value in the standby or module standby
mode.

Bit Bit

Name

Initial
Value R/W Description

31, 30

 All

0

R

Reserved

These bits are always read as 0. The write value
should always be 0.

29

28

CMS1

CMS0

0

0

R/W

R/W

Cycle Steal Mode Select 1, 0

These bits select either normal mode or intermittent
mode in cycle steal mode.

It is necessary that the bus modes of all channels be
set to cycle steal mode to make the intermittent mode
valid.

00: Normal mode

01: Reserved (Setting prohibited)

10: Intermittent mode 16

Executes one DMA transfer in each of 16 clocks of
an external bus clock.

11: Intermittent mode 64

Executes one DMA transfer in each of 64 clocks of
an external bus clock.

27, 26

 All

0

R

Reserved

These bits are always read as 0. The write value
should always be 0.

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