Intel Pentium 4 Processor CK00 Clock Synthesizer/Driver Design Guidelines

CK00 Clock Synthesizer/Driver Design Guidelines
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Table 6.2 CKx_WBY Pin Description Table
Pin Type Qty Symbol Description
45,44 Buffer X1 Host/Host_b Host pair 1
42,41 Buffer X1 Host/Host_b Host pair 2
39,38 Buffer X1 Host/Host_b Host pair 3
36,35 Buffer X1 Host/Host_b Host pair 4
33,32 Buffer X1 Host/Host_b Host pair 5
30,29 Buffer X1 Host/Host_b Host pair 6
27 Special 1 I_Ref This pin establishes the reference current for the Host
pairs. This pin takes a fixed precision resistor tied to
ground in order to establish the appropriate current.
24 Input 1 PWRDWN# Invokes power-down mode. Active Low.
23 Input 1 Spread# Invokes Spread Spectrum functionality on the Differential
Host clocks, MRef/MRef_b clocks, 66MHz clocks, and
33MHz PCI clocks. Active Low
22,21 Input 2
SelB, SelA Select pins
18,17 Input 2 MultSel0,
MultSel1
These pins configure the Ioh amplitude (and thus the
Voh swing amplitude) of the Host pair outputs
16 Input 1 SEL100/133 Host Frequency Select. Low=100MHz, High=133MHz
14 3.3V output 1 3V66 66MHz reference clock
9 3.3V output 1 3VMref 3V reference to memory clock driver
8 3.3V output 1 3VMRef_b 3V reference to memory clock driver (out of phase with
3Vmref)
5 Xtal output 1 Xtal_out 14.318MHz Crystal output
4 Xtal input 1 Xtal_in 14.318MHz Crystal input
2 3.3V output 1 Ref_out 14.318MHz reference output
48,6,3,1 Power/Gnd 3.3R,GndR Power and ground pins recommended for REF clock and
Xtal dedicated use
43,40,37,34,
31,28
Power/Gnd 3.3H, GndH Power and ground pins recommended for Host/Host_bar
dedicated use
26,25 Power/Gnd 3.3I,GndI Power and ground pins recommended for current
reference circuit dedicated use
15,13 Power/Gnd 3.3L,GndL Power and ground pins recommended for 3V66 dedicated
use
12,11 Power/Gnd 3.3Core,
GndCore
Power and ground pins recommended for dedicated core
use
10,7 Power/Gnd 3.3M, GndM Power and ground pins recommended for 3VMref and
3VMref_b dedicated use
47,20,19 Power, Gnd 3.3, Gnd Power and ground pins