Intel
®
81341 and 81342—Application DMA Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
476
Order Number: 315037-002US
5.3.4
Dual XOR Descriptor Format
The Dual XOR descriptor can be used to perform a Dual-XOR-transfer. To perform a
Dual-XOR-transfer, the Dual XOR format descriptor must be written to local memory.
shows the format of an individual Dual XOR chain descriptor. Every Dual XOR
descriptor requires 16 contiguous words in local memory and is required to be aligned
on a 32-byte address boundary. All 16 words are required.
Note:
Bits 3 down to 0 of the Horizontal Destination Address (Word 4 and 5) and the Diagonal
Destination Address (Word 14 and 15) must be programmed to the same four-bit
value.
Figure 51. Dual XOR Descriptor Format
Next Descriptor Address
H - Destination Address (Lower)
H - Destination Address (Upper)
Descriptor Control
Reserved (00000000h)
Byte Count
Word 0
Word 2
Word 1
Word 3
Word 4
Word 5
Source 0 Address (Lower)
Source 0 Address (Upper)
Word 6
Word 7
Source 1 Address (Lower)
Source 1 Address (Upper)
Word 8
Word 9
H - Source Address (Lower)
H - Source Address (Upper)
Word 10
Word 11
D - Source Address (Lower)
D - Source Address (Upper)
Word 12
Word 13
D - Destination Address (Lower)
D - Destination Address (Upper)
Word 14
Word 15
B6222-01