FW82801DBM S L6DN Intel, FW82801DBM S L6DN Datasheet - Page 104

• Manufacturer Part Number: FW82801DBM S L6DN
• Manufacturer: Intel

Specifications of FW82801DBM S L6DN

• Lead Free Status / RoHS Status: Not Compliant

Functional Description
5.5.3
5.5.4
5.5.5
104
Table 5-10. DMA Cycle vs. I/O Address
Table 5-11. PCI Data Bus vs. DMA I/O Port Size
Table 5-12. DMA I/O Cycle Width vs. BE[3:0]#
The I/O portion of the DMA cycle generates a PCI I/O cycle to one of four I/O addresses
(Table
device.
DMA Addresses
The memory portion of the cycle generates a PCI memory read or memory write bus cycle (its
address representing the selected memory). The I/O portion of the DMA cycle generates a PCI
I/O cycle to one of the four I/O addresses listed in
DMA Data Generation
The data generated by PC/PCI devices on I/O reads when they have an active GNT# is on the lower
two bytes of the PCI AD bus.
bit channels. Each I/O read results in one memory write, and each memory read results in one
I/O write. If the I/O device is 8 bit, the ICH4 performs an 8-bit memory write. The ICH4 does not
assemble the I/O read into a DWord for writing to memory. Similarly, the ICH4 does not
disassemble a DWord read from memory to the I/O device.
DMA Byte Enable Generation
The byte enables generated by the ICH4 on I/O reads and writes must correspond to the size of the
I/O device.
NOTE: For verify cycles the value of the Byte Enables (BEs) is a “don’t care”.
DMA Cycle Type
5-10). Note that these cycles must be qualified by an active GNT# signal to the requesting
Normal TC
Verify TC
Normal
Verify
Table 5-12
PCI DMA I/O Port Size
BE[3:0]#
1100b
1110b
Word
Byte
defines the byte enables asserted for 8-bit and 16-bit DMA cycles.
DMA I/O Address
Table 5-11
0C0h
0C4h
00h
04h
lists the PCI pins that the data appears on for 8-bit and 16-
Table
PCI Cycle Type
I/O Read/Write
I/O Read/Write
5-10.
I/O Read
I/O Read
16-bit DMA I/O Cycle: Channels 5-7
8-bit DMA I/O Cycle: Channels 0-3
PCI Data Bus Connection
Intel
®
Description
82801DBM ICH4-M Datasheet
AD[15:0]
AD[7:0]