Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
473
Application DMA Unit—Intel
®
81341 and 81342
Each word in P+Q chain descriptor is analogous to control register values. Bit
definitions for words in the chain descriptor are the same as for the control registers.
• First word is local memory address of next chain descriptor. A value of ‘0’ specifies
the end of chain. This value is loaded into the ADMA Next Descriptor Address
Register. Because basic chain descriptors must be aligned on an 8-word boundary,
the unit may ignore bits 04:00 of this address.
Figure 50. P+Q Chain Descriptor Format (Minimum Size)
B6221-01
Source 8 Address (Lower)
Source 14 Address (Lower)
Source 9 Address (Lower)
Word 22
Word 23
Word 25
Word 24
Word 35
Word 34
Source 10 Address (Lower)
Word 27
Word 26
Source 11 Address (Lower)
Word 29
Word 28
Source 12 Address (Lower)
Word 31
Word 30
Source 13 Address (Lower)
Word 33
Word 32
Source 15 Address (Lower)
Word 37
Word 36
DMLT13
Source 13 Address (Upper)
DMLT12
Source 12 Address (Upper)
DMLT11
Source 11 Address (Upper)
DMLT10
Source 10 Address (Upper)
DMLT9
Source 9 Address (Upper)
DMLT8
Source 8 Address (Upper)
DMLT14
Source 14 Address (Upper)
DMLT15
Source 15 Address (Upper)
Next Descriptor Address
P_Destination Address (Lower)
PQ_Destination Address (Upper)
Source 0 Address (Lower)
Descriptor Control
Q_Destination Address (Lower)
Byte Count
Word 0
Word 2
Word 1
Word 3
Word 4
Word 6
Word 5
Word 7
DMLT0
Source 0 Address (Upper)
Source 1 Address (Lower)
Source 7 Address (Lower)
Source 2 Address (Lower)
Word 8
Word 9
Word 11
Word 10
Word 21
Word 20
Source 3 Address (Lower)
Word 13
Word 12
Source 4 Address (Lower)
Word 15
Word 14
Source 5 Address (Lower)
Word 17
Word 16
Source 6 Address (Lower)
Word 19
Word 18
DMLT6
Source 6 Address (Upper)
DMLT5
Source 5 Address (Upper)
DMLT4
Source 4 Address (Upper)
DMLT3
Source 3 Address (Upper)
DMLT2
Source 2 Address (Upper)
DMLT1
Source 1 Address (Upper)
DMLT7
Source 7 Address (Upper)