
Chapter 2
Signal Descriptions
27
24674
Rev. 3.00
April 2003
AMD-8111 HyperTransport I/O Hub Data Sheet
AMD Preliminary Information
PWROK.
Power OK. This is required to be Low while the
main power planes are not valid, stay Low for at least 50
milliseconds after they become valid, and then go High. It is
the reset source for the main power supplies of the IC,
VDD_CORE and VDD_IO. The logic for this pin includes a
debounce circuit. When the signal is asserted High for less
than 30 microseconds, the debounce logic does not
propagate a change of the signal value to the internal logic;
the signal must be asserted for at least 60 microseconds to
be safely detected by the internal logic.
PWRON_L.
Main power on. This is expected to control the
main power supplies to the system board. It is asserted
during the FON, C2, C3, and POS states; it is deasserted
during the STR, STD and SOFF states. When power is
applied to the AUX plane, this signal is forced inactive until
RST_SOFT is deasserted. See Section 3.7.1.6.2 on page 60
for more details.
RESET_L.
System reset. This is the system reset signal for
logic that is powered by the main power supplies. See
Section 3.1.1 on page 37 and Section 3.7.1.6.2 on page 60
for more details.
RI_L.
Ring indicate. This is intended to cause the system to
resume to the FON states and generate SCI or SMI
interrupts. It controls PM20[RI_STS].
RPWRON.
RAM power on. This is intended to control power
to the system memory power plane. When High, it is
expected that power to system memory is enabled. When
Low, it is expected that power to system memory is disabled.
This pin is Low during STD and SOFF and High in all other
states. See Section 3.7.1.6.2 on page 60 for more details.
RTCX_IN.
Real-time clock 32.768 kHz crystal input. This pin
is expected to be connected through a crystal oscillator to
RTCX_OUT.
RTCX_OUT.
Real-time clock 32.768 kHz crystal output.
I
VDD_
IOX
OD
VDD_
IOX
3-State
Low
Low
3-State
O
VDD_
IOX
Func.
Func.
High
Low
I
VDD_
IOX
OD
VDD_
IOX
Func. 3-State 3-State Func.
A
VDD_
IOAL
Func.
Func.
Func.
Func.
A
VDD_
IOAL
VDD_
IOX
VDD_
IOX
VDD_
IO
Func.
Func.
Func.
Func.
S3PLL_LF.
S3PLL external loop filter pin.
A
Func.
Func.
Func.
Func.
S3PLL_LF_VSS.
S3PLL external loop filter pin.
A
Func.
Func.
Func.
Func.
SERIRQ.
Serial IRQ signal. This pin supports the serial IRQ
protocol. Control for this is in DevB:3x4A.
IO
3-State 3-State Func.
Table 6.
System Management Pin Descriptions (Continued)
Pin Name and Description
I/O
Cell
Type
Power
Plane
During
Reset
After
Reset
During
POS
During
S3:S5