cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 177

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

Revision 0.8
GLCP Functional Description
2)
3)
If a debug event in the debug circuitry triggers a clock
disable,
GLCP_CLKDISABLE. Each GLCP_CLKDISABLE bit
corresponds to a CCU, and when set, indicates that
the clock going to that CCU should be disabled.
Each bit in GLCP_CLKOFF (MSR 51700010h) corre-
sponds to a CCU. When set, the bit indicates that the
clock going to that CCU should be disabled. This is the
simplest case.
– If Sleep Acknowledge is asserted and the clock
disable delay period is not enabled, check to see if
all clocks specified by GLCP_CLK4ACK (MSR
51700013h) have become inactive. If
GLCP_CLKACTIVE (MSR 51700011h) shows that
those clocks are indeed inactive, disable the
clocks specified in GLCP_PMCLKDISABLE (MSR
51700009h).
Sleep Acknowledge is asserted after the clocks
have been disabled. The wakeup sequence is trig-
gered by the de-assertion of the Sleep Request,
which turns on all the clocks.
disable
all
the
clocks
(Continued)
specified
in
177
4.19.2 GLCP Clocks
The GLCP has multiple clock domains, namely the
GeodeLink clock and PCI clock. The GeodeLink clock is
the clock source for the MSRs, the serial interface, and the
GeodeLink interface. The PCI clock is used in the power
management support for the clock disable delay timer. Both
the GeodeLink and PCI functional clocks come from pri-
mary inputs. All these clocks are handled by a CCU. Even
though the PCI clock is always running in functional mode,
a CCU is needed to be able to perform reset synchroniza-
tion and to turn off the internal clock to support TAPSCAN.
The CCUs used by the GLCP are the asynchronous ver-
sions, since the GLCP outputs asynchronous busy signals.
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