307013-003 Datasheet, PDF (400/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

LPC Interface Bridge Registers (D31:F0)
10.4.7
OCW1—Operational Control Word 1 (Interrupt Mask)
Register (LPC I/F—D31:F0)
Offset Address: Master Controller – 021h
Slave Controller – 0A1h
Default Value: 00h
Attribute:
Size:
R/W
8 bits
10.4.8
Bit
Description
Interrupt Request Mask — R/W. When a 1 is written to any bit in this register, the
corresponding IRQ line is masked. When a 0 is written to any bit in this register, the
7:0 corresponding IRQ mask bit is cleared, and interrupt requests will again be accepted by
the controller. Masking IRQ2 on the master controller will also mask the interrupt
requests from the slave controller.
OCW2—Operational Control Word 2 Register
(LPC I/F—D31:F0)
Offset Address: Master Controller – 020h Attribute:
Slave Controller – 0A0h Size:
Default Value: Bit[4:0]=undefined, Bit[7:5]=001
WO
8 bits
Following a part reset or ICW initialization, the controller enters the fully nested mode
of operation. Non-specific EOI without rotation is the default. Both rotation mode and
specific EOI mode are disabled following initialization.
Bit
Description
Rotate and EOI Codes (R, SL, EOI) — WO. These three bits control the Rotate and
End of Interrupt modes and combinations of the two.
000 = Rotate in Auto EOI Mode (Clear)
001 = Non-specific EOI command
010 = No Operation
7:5 ^{011 = *Specific EOI Command}
100 = Rotate in Auto EOI Mode (Set)
101 = Rotate on Non-Specific EOI Command
110 = *Set Priority Command
111 = *Rotate on Specific EOI Command
*L0 – L2 Are Used
4:3 OCW2 Select — WO. When selecting OCW2, bits 4:3 = “00”
Interrupt Level Select (L2, L1, L0) — WO. L2, L1, and L0 determine the interrupt
level acted upon when the SL bit is active. A simple binary code, outlined below, selects
the channel for the command to act upon. When the SL bit is inactive, these bits do not
have a defined function; programming L2, L1 and L0 to 0 is sufficient in this case.
2:0
Code Interrupt Level
000b
IRQ0/8
001b
IRQ1/9
010b
IRQ2/10
011b
IRQ3/11
Code
000b
001b
010b
011b
Interrupt Level
IRQ4/12
IRQ5/13
IRQ6/14
IRQ7/15
400
Intel ^® ICH7 Family Datasheet