Datasheet

Mobile Intel

Pentium

III Processor in BGA2 and Micro-PGA2 Packages at 1 GHz,

900 MHz, 850 MHz, 800 MHz, 750 MHz, 700 MHz, Low-voltage 750 MHz, Low-voltage 700 MHz,

Low-voltage 600 MHz, Ultra Low-voltage 600 MHz and Ultra Low-voltage 500 MHz

70 Datasheet 283653-002

Table 36. BSEL[1:0] Encoding

BSEL[1:0] System Bus Frequency

00 66 MHz

01 100 MHz

10 Reserved

11 133 MHz

CLKREF (Analog)

The CLKREF (System Bus Clock Reference) signal provides a reference voltage to define the trip

point for the BCLK signal. This signal should be connected to a resistor divider to generate 1.25V

from the 2.5-V supply.

CMOSREF (Analog)

The CMOSREF (CMOS Reference Voltage) signal provides a DC level reference voltage for the

CMOS input buffers. A voltage divider should be used to divide a stable voltage plane (e.g., 2.5V

or 3.3V). This signal must be provided with a DC voltage that meets the V

CMOSREF

specification

from Table 12.

D[63:0]# (I/O - GTL+)

The D[63:0]# (Data) signals are the data signals. These signals provide a 64-bit data path between

both system bus agents, and must be connected to the appropriate pins/balls on both agents. The

data driver asserts DRDY# to indicate a valid data transfer.

DBSY# (I/O - GTL+)

The DBSY# (Data Bus Busy) signal is asserted by the agent responsible for driving data on the

system bus to indicate that the data bus is in use. The data bus is released after DBSY# is

deasserted. This signal must be connected to the appropriate pins/balls on both agents on the

system bus.

DEFER# (I - GTL+)

The DEFER# (Defer) signal is asserted by an agent to indicate that the transaction cannot be

guaranteed in-order completion. Assertion of DEFER# is normally the responsibility of the

addressed memory agent or I/O agent. This signal must be connected to the appropriate pins/balls

on both agents on the system bus.

DEP[7:0]# (I/O - GTL+)

The DEP[7:0]# (Data Bus ECC Protection) signals provide optional ECC protection for the data

bus. They are driven by the agent responsible for driving D[63:0]#, and must be connected to the