Programming Model
http://www.mcg.mot.com/literature
4-29
4
DMA Arbitration Control Register
The DMA arbitration control register contents determine whether a fixed
or fair arbitration algorithm is used to determine how the MC68060 local
bus is attached to the internal DMA data paths.
ROTAT
ROTAT set to a zero enables a rotating arbitration method
where each DMAC has equal access to the MC68060
local bus. If ROTAT is set to a one, the priority is fixed
according to the following table
PRI1,PRI0
Fixed priority assignment is defined by the following
tables.
ADR/SIZ
$FFFBC01E (8 bits)
BIT
7
6
5
4
3
2
1
0
NAME
0
0
0
0
0
ROTAT
PRI1
PRI0
OPER
R
R
R
R
R
R/W
R/W
R/W
RESET
0 R
0 R
0 R
0 R
0 R
0 R
0 R
0 R
PRI1 - PRI0
Priority with one DMA channel at IP sockets a, b, c, & d
Highest
Next Highest
Next Lowest
Lowest
00
DMA_a
DMA_b
DMA_c
DMA_d
01
DMA_b
DMA_c
DMA_d
DMA_a
10
DMA_c
DMA_d
DMA_a
DMA_b
11
DMA_d
DMA_a
DMA_b
DMA_c
PRI1 - PRI0
Priority with two DMA channel at IP sockets a and c
Highest
Next Highest
Next Lowest
Lowest
00
DMA_a chan 0
DMA_a chan 1
DMA_c chan 0
DMA_c chan 1
01
DMA_a chan 1
DMA_c chan 0
DMA_c chan 1
DMA_a chan 0
10
DMA_c chan 0
DMA_c chan 1
DMA_a chan 0
DMA_a chan 1
11
DMA_c chan 1
DMA_a chan 0
DMA_a chan 1
DMA_c chan 0
Summary of Contents for MVME172
Page 6: ...Place holder ...
Page 18: ...xviii ...
Page 78: ...1 60 Computer Group Literature Center Web Site Board Description and Memory Maps 1 ...
Page 332: ...5 42 Computer Group Literature Center Web Site MCECC 5 ...
Page 336: ...A 4 Related Documentation A ...
Page 352: ...Index IN 12 Computer Group Literature Center Web Site I N D E X ...
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