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3 channel priority – Renesas SH7641 User Manual

Page 479

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Section 13 Direct Memory Access Controller (DMAC)

Rev. 4.00 Sep. 14, 2005 Page 429 of 982

REJ09B0023-0400

CHCR DMARS

RS[3:0] MID

RID

DMA
Transfer
Request
Source

DMA Transfer
Request Signal

Source

Desti-
nation Bus

Mode

1000

101010

00

MTU0

TGI0A
(input capture interrupt/
compare match interrupt)

Any Any Burst/

cycle steal

110000

00

MTU1 TGI1A

(input capture interrupt/
compare match interrupt)

Any Any Burst/

cycle steal

110010

00

MTU2 TGI2A

(input capture interrupt/
compare match interrupt)

Any Any Burst/

cycle steal

110100

00

MTU3 TGI3A

(input capture interrupt/
compare match interrupt)

Any Any Burst/

cycle steal

111010

00

MTU4 TGI4A

(input capture interrupt/
compare match interrupt)

Any Any Burst/

cycle steal

101000 00

USB transmitter EP2FIFO empty transfer

request

Any USBEPDR2

Cycle

steal

01

USB

receiver

EP1FIFO full transfer
request

USBEPDR1 Any Cycle

steal

101100 00

A/D converter 1 ADI (A/D conversion

end interrupt)

ADDR1 Any

Cycle

steal

111100 00 CMT1

Compare-match

transfer

request

Any Any Burst/

cycle steal

13.4.3 Channel

Priority

When the DMAC receives simultaneous transfer requests on two or more channels, it selects a
channel according to a predetermined priority order. The four modes (fixed mode 1, fixed mode 2,
channel selective round-robin mode, and all-channel round-robin mode) are selected using the
priority bits PR0, PR1, and RC0 to RC3 in the DMA operation register (DMAOR).

Fixed Mode: In these modes, the priority levels among the channels remain fixed. There are two
kinds of fixed modes as follows:

Fixed mode 1: CH0 > CH1 > CH2 > CH3

Fixed mode 2: CH0 > CH2 > CH3 > CH1

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