Signal Description
R
28 Intel® 82845 MCH for SDR Datasheet
2.5 Clocks, Reset, and Miscellaneous Signals
Signal Name Type Description
BCLK
BCLK#
I
CMOS Differential Host Clock In: These pins recei ve a di f f erential host clock
from the external clock synthesizer. This clock is used by all of the MCH
logic that is in the host clock domain.
66IN I
CMOS 66 MHz Clock In: This pin receives a 66 MHz cloc k from the clock
synthesizer. This clock is used by AGP/PCI and hub interface clock
domains.
Note: That this clock input is 3.3 V tolerant.
SCK[11:0] O
CMOS System Memory Clocks (SDR): These signals deliver a synchronized
clock to the DIMMs. There are two per row.
RSTIN# I
CMOS Reset In: When asserted, this signal asynchronously resets the MCH
logic. RSTIN# is connected to the PCIRST# output of the ICH2. All
AGP/PCI output and bi-directional signals will also three-state compliant
to PCI Rev 2.0 and 2.1 specifications.
Note: This input needs to be 3.3 V tolerant.
TESTIN# I
CMOS Test Input: This pin is used for manufacturing and board level tes t
purposes.
Note: This signal has an internal pull-up resistor.