FW82801BA S L5PN Intel, FW82801BA S L5PN Datasheet - Page 110
FW82801BA S L5PN
Manufacturer Part Number
FW82801BA S L5PN
Description
Manufacturer
Intel
Datasheet
1.FW82801BA_S_L5PN.pdf
(671 pages)
Specifications of FW82801BA S L5PN
Lead Free Status / RoHS Status
Not Compliant
- Current page: 110 of 671
- Download datasheet (8Mb)
Functional Description
5.5.1
5.5.1.1
5.5.1.2
5.5.2
110
Channel Priority
For priority resolution, the DMA consists of two logical channel groups: channels 0–3 and
channels 4–7. Each group may be in either fixed or rotate mode, as determined by the DMA
Command Register.
DMA I/O slaves normally assert their DREQ line to arbitrate for DMA service. However, a
software request for DMA service can be presented through each channel's DMA Request Register.
A software request is subject to the same prioritization as any hardware request. See the detailed
register description for Request Register programming information in the
Fixed Priority
The initial fixed priority structure is as follows:
The fixed priority ordering is 0, 1, 2, 3, 5, 6, and 7. In this scheme, channel 0 has the highest
priority, and channel 7 has the lowest priority. Channels [3:0] of DMA-1 assume the priority
position of channel 4 in DMA-2, thus taking priority over channels 5, 6, and 7.
Rotating Priority
Rotation allows for "fairness" in priority resolution. The priority chain rotates so that the last
channel serviced is assigned the lowest priority in the channel group (0–3, 5–7).
Channels 0–3 rotate as a group of 4. They are always placed between channel 5 and channel 7 in
the priority list.
Channel 5–7 rotate as part of a group of 4. That is, channels (5–7) form the first three positions in
the rotation, while channel group (0–3) comprises the fourth position in the arbitration.
Address Compatibility Mode
When the DMA is operating, the addresses do not increment or decrement through the High and
Low Page Registers. Therefore, if a 24-bit address is 01FFFFh and increments, the next address is
010000h, not 020000h. Similarly, if a 24-bit address is 020000h and decrements, the next address
is 02FFFFh, not 01FFFFh. However, when the DMA is operating in 16-bit mode, the addresses still
do not increment or decrement through the High and Low Page Registers but the page boundary is
now 128 K. Therefore, if a 24-bit address is 01FFFEh and increments, the next address is 000000h,
not 0100000h. Similarly, if a 24-bit address is 020000h and decrements, the next address is
03FFFEh, not 02FFFEh. This is compatible with the 82C37 and Page Register implementation
used in the PC-AT. This mode is set after CPURST is valid.
High priority
0, 1, 2, 3
Low priority
5, 6, 7
Intel
®
82801EB ICH5 / 82801ER ICH5R Datasheet
Section
9.2.
Related parts for FW82801BA S L5PN
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Intel
Datasheet:
Part Number:
Description:
Manufacturer:
Intel
Datasheet:
Part Number:
Description:
Manufacturer:
Intel
Datasheet:
Part Number:
Description:
Manufacturer:
Intel
Datasheet:
Part Number:
Description:
Microprocessor: Intel Celeron M Processor 320 and Ultra Low Voltage Intel Celeron M Processor at 600MHz
Manufacturer:
Intel Corporation
Part Number:
Description:
Intel 82550 Fast Ethernet Multifunction PCI/CardBus Controller
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
Intel StrataFlash memory 32 Mbit. Access speed 120 ns
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
Intel StrataFlash memory 32 Mbit. Access speed 120 ns
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
Intel StrataFlash memory 64 Mbit. Access speed 150 ns
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
Intel StrataFlash memory 32 Mbit. Access speed 100 ns
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
DA28F640J5A-1505 Volt Intel StrataFlash Memory
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
5 Volt Intel StrataFlash?? Memory
Manufacturer:
Intel Corporation
Datasheet:
Part Number:
Description:
5 Volt Intel StrataFlash?? Memory
Manufacturer:
Intel Corporation