Intel 810A3, Design Manual

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Design Checklist
8-8 Intel
®
810A3 Chipset Design Guide
Table 8-11. ICH Checklist
Checklist Line Items Comments
PME#, PWRBTN#,
LAD[3:0]#/FWH[3:0]#
No external pullup resistors on those signals with integrated pullups.
SPKR
Optional strapping: Internal pullup resistor is enabled at reset for strapping; after reset,
the internal pullup resistor is disabled.
Otherwise, connect to motherboard speaker logic.
AC_SDOUT
Optional strapping: Internal pulldown resistor is enabled at reset for strapping. after
reset, the internal pulldown resistor is disabled.
Otherwise, connect to AC’97 logic.
AC_BITCLK
Internal pulldown resistor is enabled only when the AC link shut-off bit in the ICH is set.
Otherwise, connect to AC’97 logic.
AC_SDIN[1:0]
Internal pulldown resistors are enabled only when the AC link shut-off bit in the ICH is
set.
Use 10K ohm (approximate) pulldown resistors on both signals if using AMR.
For onboard AC’97 devices, use a 10K ohm (approximate) pulldown resistor on the
signal that is not used.
Otherwise, connect to AC’97 logic.
PDD[15:0], PDIOW#,
PDIOR#, PDREQ,
PDDACK#, PIORDY,
PDA[2:0], PDCS1#,
PDCS3#, SDD[15:0],
SDIOW#, SDIOR#,
SDREQ, SDDACK#,
SIORDY, SDA[2:0],
SDCS1#, SDCS3#,
IRQ14, IRQ15
No external series termination resistors on those signals with integrated series
resistors.
PCIRST# The PCIRST# signal should be buffered to the IDE connectors.
No floating inputs
(including bi-
directional signals):
Unused core well inputs should be tied to a valid logic level (either pulled up to 3.3V or
pulled down to ground). Unused resume well inputs must be either pulled up to
3.3VSB or pulled down to ground.
Ensure ALL unconnected signals are OUTPUTS ONLY!
PDD[15:0],
SDD[15:0]
PDD7 and SDD7 need a 10 K
Ω
(approximate) pulldown resistor.
No other pullups/pulldowns are required.
Refer to ATA ATAPI-4 specification.
PIORDY, SDIORDY Use approximately 1 K
Ω
pullup resistor to 5V.
PDDREQ, SDDREQ Use approximately 5.6 K
Ω
pulldown resistor to ground.
IRQ14, IRQ15 Need 8.2K ohm (approximate) pullup resistor to 5V.
HL11
No pullup resistor required.
A test point or no-stuff resistor is needed to be able to drive the ICH into NAND tree
mode for testing purposes.
VccRTC
No Clear CMOS Jumper on VccRTC. Use a jumper on RTCRST# or a GPI, or use a
safe-mode strapping for Clear CMOS.
SMBus:
SMBCLK
SMBDATA
The SMBus signals can be pulled up to VCC3.3 standby. Isolate any devices that are
not on the same power plane as the SMBus pullups in any states where VCC3.3
standby is on and VCC3.3 is off.
The value of the SMBus pullups should reflect the number of loads on the bus. For
most implementations with 4–5 loads, 4.7 K
Ω
resistors are recommended. OEMs
should conduct simulation to determine exact resistor value.