
Chapter 3
Functional Operation
63
24674
Rev. 3.00
April 2003
AMD-8111 HyperTransport I/O Hub Data Sheet
AMD Preliminary Information
response message to the read of PM14 or PM15. The IC then waits for a Stop Grant special cycle
broadcast message from the host. When the IC receives the broadcast Stop Grant message, the
transition to C2 is complete; the remaining steps only apply to the transition to C3.
AGPSTOP_L.
If DevB:3x4F[ASTP_C3EN]=1b, the IC asserts AGPSTOP_L when it recognizes
the Stop Grant special cycle associated with the C3 state.
CPUSLEEP_L.
If DevB:3x4F[CSLP_C3EN]=1b, the IC asserts CPUSLEEP_L when it
recognizes the Stop Grant special cycle associated with the C3 state.
LDTSTOP_L.
After the Stop Grant special cycle is recognized, the IC waits the time interval
dictated by DevB:3x74[C3S1LST], then if DevB:3x70[C3LS]=1b the IC asserts LDTSTOP_L.
3.7.1.6.5
Transitions From C2 to C0 (FON)
When the IC detects an enabled resume event, it issues a HyperTransport STPCLK system
management message with the STPCLK bit deasserted.
3.7.1.6.6
Transitions From C3 to C0 (FON)
The following is the resume sequence from C3, once an enabled resume event occurs. Note: if
CPUSLEEP_L is not enabled to be asserted in C3 by DevB:3x4F, then the C3 resume sequence starts
from “LDTSTOP_L” below:
CPUSLEEP_L.
If DevB:3x4F[CSLP_C3EN]=1b then, when an enabled resume event occurs,
CPUSLEEP_L is deasserted and a 250
μ
s delay is inserted before the rest of the C3 resume
sequence occurs. If DevB:3x4F[CSLP_C3EN]=0b then CPUSLEEP_L is not part of the C3
sequence, and the 250
μ
s delay is not inserted between recognizing an enabled resume event, and
deassertion of LDTSTOP_L.
LDTSTOP_L.
If DevB:3x70[C3LS]=1b then LDTSTOP_L is deasserted when the IC detects an
enabled resume event (unless CPUSLEEP_L was asserted). See DevB:3x74[FVLST].
AGPSTOP_L.
If CPUSLEEP_L is used and LDTSTOP_L is not used then AGPSTOP_L is
deasserted 250
μ
s after CPUSLEEP_L deassertion (as mentioned above). If LDTSTOP_L is used
then after LDTSTOP_L deassertion a delay dictated by DevB:3x52[C3_ASTP_DT] occurs before
AGPSTOP_L is deasserted. If LDTSTOP_L and CPUSLEEP_L are not used then after a
programmable time period dictated by DevB:3x52[C3_ASTP_DT] after the resume event
AGPSTOP_L is deasserted.
After LDTSTOP_L and AGPSTOP_L are deasserted, the IC issues a HyperTransport STPCLK
system management message with the STPCLK bit deasserted.
3.7.1.6.7
Transitions From FON (S0/C0) to POS (S1)
DevB:3x50 specifies the enabled functions for transitions to S1. The transition to S1 occurs as follows
for each of the enabled pin controls:
Processor initiation.
Software initiates the transition to S1 by writing the appropriate value to
PM04[SLP_TYP, SLP_EN].