Ck408 Vs. Ck408B Requirement; Stuffing Options For Ck408 And Ck408B - Intel Pentium M Processor Design Manual

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Intel Pentium M Processor and Intel
Platform Clock Routing Guidelines
4.2.3

CK408 vs. CK408B Requirement

The CK408 and CK408B are pin compatible. The only difference between the two chips is the
CK408B replaces two signals on the CK408 with a fourth HOST_CLK pair. The fourth
HOST_CLK pair is connected to the debug port also known as the In Target Probe (ITP). The ITP
is preferred by board designers for preliminary testing and validation. While the CK408B's fourth
HOST_CLK pair pins are connected to the ITP, the CK408 pins require the following stuffing
options:
Add one 10 kΩ ± 5% pull-up resistor close to the clock driver before the 33 Ω ± 5% (Rs)
•
(see
option to use the CK408 instead of the CK408B.
•
When using a CK408, the 10 kΩ ± 5% pull-up resistors are the only necessary parts.
•
Each unused clock output needs one 10 kΩ ± 5% pull-up resistor close to the clock driver.
Figure 11.

Stuffing Options for CK408 and CK408B

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E7501 Chipset Platform
Figure 11) series resistor on each ITP signal trace (CPU3, CPU3#). This would give the
CK408x
CPU3 / S0
CPU3# /
CPU_STOP#
VCC3_3
CK408: 10 kΩ ± 5%
CK408B: no pop
To ITP BCLK1
CK408: no pop
CK408B: Rs
VCC3_3
CK408: 10 kΩ ± 5%
CK408B: no pop
To ITP BCLK1
CK408: no pop
CK408B: Rs
Design Guide