cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 348

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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KEL Register Descriptions
5.10.1 KEL Specific MSRs
5.10.1.1
MSR Address
Type
Reset Value
Port A operation is not effected by Snoop or EmulationEnable settings in KELX_CTL. Bits [31:5] are Reserved. Writes are
“don’t care” and reads always return zero.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
31:5
Bit
3:2
4
1
0
Keyboard Emulation Logic Control Register (KELX_CTL)
Name
RSVD
PRTA_EN
SOFEVENT
EER
SNOOP
5140001Fh
R/W
00000010h
Description
Reserved. Writes have no effect; reads return 0.
Port A Enable. Defaults high. If high, Port A is enabled and accesses to I/O Port 092h
are processed by the CS5535. If low, accesses to I/O Port 092h are passed on to the
LPC bus (where Port A may exist inside a SuperI/O).
Start-Of-Frame (SOF) Event (SOFEVENT) Selection.
00: Test Mode (No delays).
01: USB1 (Default).
10: USB2.
11: 1 ms from PIT.
Emulation Event (EE) Routing.
0: Emulation Interrupt and ASMI.
1: ASMI only.
The EER bit controls keyboard emulation interrupt generation associated with EEs:
• Character Pending - Clear EE by setting the Outputfull bit in the HCE_Status register
• Input Full - Clear EE by clearing the InputFull bit in HCE_Status.
• External IRQ - Clear EE by clearing IRQ1Active or IRQ12Active as appropriate in
Snoop. Only applies when EmulationEnable in HCE_Control is low. When high, indi-
cates A20 and Init keyboard sequences are to be detected on I/O Port 060h/064h
transactions to the LPC keyboard. KEL must generate ASMI upon detection of A20 and
Init even though EmulationEnable in HCE_Control is low.
Emulation
Enable Snoop
or clearing the CharacterPending bit in HCE_Control.
HCE_Control.
0
1
0
(Continued)
KELX_CTL Bit Descriptions
KELX_CTL Register Map
1
x
0
RSVD
PORTA_A20_ASMI or KEL_INIT_ASMI is generated when sequence
is detected. Status of ASMI Flag and Enable bits are in DIVIL MSR
51400002h.
PORTA_A20_ASMI or KEL_INIT_ASMI is generated when sequence
is detected. KEL_ASMI is generated on InputFull, External IQ, or
Character Pending. Status of ASMI Flag and Enable bits are in DIVIL
MSR 51400002h For the A20 keyboard sequence, both KEL_ASMI
and PORTA_A20_ASMI are signaled.
OFF.
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