307013-003 Datasheet, PDF (5/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

5.6
5.7
5.8
5.9
5.10
DMA Operation (D31:F0) .................................................................................. 124
5.6.1 Channel Priority ................................................................................... 124
5.6.1.1 Fixed Priority.......................................................................... 125
5.6.1.2 Rotating Priority ..................................................................... 125
5.6.2 Address Compatibility Mode ................................................................... 125
5.6.3 Summary of DMA Transfer Sizes ............................................................. 125
5.6.3.1 Address Shifting When Programmed for 16-Bit I/O Count by
Words ................................................................................... 126
5.6.4 Autoinitialize........................................................................................ 126
5.6.5 Software Commands............................................................................. 126
LPC DMA (Desktop and Mobile Only) .................................................................. 127
5.7.1 Asserting DMA Requests........................................................................ 127
5.7.2 Abandoning DMA Requests .................................................................... 127
5.7.3 General Flow of DMA Transfers ............................................................... 128
5.7.4 Terminal Count .................................................................................... 128
5.7.5 Verify Mode ......................................................................................... 128
5.7.6 DMA Request Deassertion...................................................................... 129
5.7.7 SYNC Field / LDRQ# Rules ..................................................................... 129
8254 Timers (D31:F0) ..................................................................................... 130
5.8.1 Timer Programming .............................................................................. 131
5.8.2 Reading from the Interval Timer............................................................. 132
5.8.2.1 Simple Read........................................................................... 132
5.8.2.2 Counter Latch Command.......................................................... 132
5.8.2.3 Read Back Command .............................................................. 132
8259 Interrupt Controllers (PIC) (D31:F0) .......................................................... 133
5.9.1 Interrupt Handling................................................................................ 134
5.9.1.1 Generating Interrupts.............................................................. 134
5.9.1.2 Acknowledging Interrupts ........................................................ 134
5.9.1.3 Hardware/Software Interrupt Sequence ..................................... 135
5.9.2 Initialization Command Words (ICWx) ..................................................... 135
5.9.2.1 ICW1 .................................................................................... 135
5.9.2.2 ICW2 .................................................................................... 136
5.9.2.3 ICW3 .................................................................................... 136
5.9.2.4 ICW4 .................................................................................... 136
5.9.3 Operation Command Words (OCW) ......................................................... 136
5.9.4 Modes of Operation .............................................................................. 136
5.9.4.1 Fully Nested Mode................................................................... 136
5.9.4.2 Special Fully-Nested Mode........................................................ 137
5.9.4.3 Automatic Rotation Mode (Equal Priority Devices)........................ 137
5.9.4.4 Specific Rotation Mode (Specific Priority).................................... 137
5.9.4.5 Poll Mode ............................................................................... 137
5.9.4.6 Cascade Mode ........................................................................ 138
5.9.4.7 Edge and Level Triggered Mode................................................. 138
5.9.4.8 End of Interrupt (EOI) Operations ............................................. 138
5.9.4.9 Normal End of Interrupt........................................................... 138
5.9.4.10 Automatic End of Interrupt Mode .............................................. 138
5.9.5 Masking Interrupts ............................................................................... 139
5.9.5.1 Masking on an Individual Interrupt Request ................................ 139
5.9.5.2 Special Mask Mode.................................................................. 139
5.9.6 Steering PCI Interrupts ......................................................................... 139
Advanced Programmable Interrupt Controller (APIC) (D31:F0) .............................. 140
5.10.1 Interrupt Handling................................................................................ 140
5.10.2 Interrupt Mapping ................................................................................ 140
5.10.3 PCI / PCI Express* Message-Based Interrupts .......................................... 141
5.10.4 Front Side Bus Interrupt Delivery ........................................................... 141
5.10.4.1 Edge-Triggered Operation......................................................... 142
Intel ^® ICH7 Family Datasheet
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