Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
479
Application DMA Unit—Intel
®
81341 and 81342
Each word in the P+Q Update chain descriptor is analogous to control register values. A
chain descriptor is interpreted as a P+Q Update operation when bit 16 of the second
word in the descriptor is set; note that this is analogous to bit 16 of the
Descriptor Control Register x — ADCRx” on page 526
.
• First word is the local memory address of the next chain descriptor. A value of zero
specifies the end of the 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.
• Second word is the Descriptor Control Word. This word configures the Application
DMA for one operation. This value is loaded into the ADMA Descriptor Control
Register.
• Third word is Reserved and must be written with 0000 0000H.
• Fourth word contains the 24-bit, Byte Count value. This value specifies the number
of bytes of data in the current chain descriptor. Also, the upper byte of this word is
the Transfer Status field that may be written back to the Byte Count Word at the
end of the ADMA transfer when the Status Write Back Enable in the ADCR is set.
This value is loaded into the ADMA Byte Count Register.
• Fifth word is the lower 32-bit P destination address. The ADMA uses this value for
the lower 32-bits of the P destination address for the P+Q-Update-Transfer
operation. This value is loaded into the Destination Lower Address Register.
• Sixth word is the upper 32-bit P destination address. The ADMA uses this value for
the upper 32-bits of the P destination address for the P+Q-Update-Transfer
operation. This value is loaded into the Destination Upper Address Register.
• Seventh word is the P+Q-Update-Transfer operation lower 32-bit source address
for the first data block. This value is loaded into the Source Lower Address
Register 0.
• Eighth word is the P+Q-Update-Transfer operation upper 32-bit source address for
the first data block. This value is loaded into the Source Upper Address Register 0.
• Ninth word is the P+Q-Update-Transfer operation lower 32-bit source address for
the second data block. This value is loaded into the Source Lower Address
Register 1.
• Tenth word is the P+Q-Update-Transfer operation upper 32-bit source address for
the second data block. This value is loaded into the Source Upper Address
Register 1.
• Eleventh word is the lower 32-bit source address for P source of the P+Q-Update-
Transfer operation. This value is loaded into the Source Lower Address Register 2.
• Twelfth word is the P+Q-Update-Transfer operation upper 32-bit source address for
the P source. This value is loaded into the Source Upper Address Register 2.
• Thirteenth word is the P+Q-Update-Transfer operation lower 32-bit source address
for Q source. This value is loaded into the Source Lower Address Register 3.
• Fourteenth word is the upper 32-bit source address and the 8-bit Q Update
Multiplier for the Q source of the P+Q-Update-Transfer operation. This value is
loaded into the Source Upper Address Register 3.
• Fifteenth word is the P+Q-Update-Transfer operation lower 32-bit destination
address for the Q destination. This value is loaded into the Source Lower Address
Register 4.
• Sixteenth word is the P+Q-Update-Transfer operation upper 32-bit destination
address for the Q destination. This value is loaded into the Source Upper Address
Register 4.