Specifications

PENTIUM® PRO PROCESSOR AT 150, 166, 180, and 200 MHz E
36
Table 17. Flexible Motherboard (FMB) Power Recommendations
1
Symbol Parameter Low End
High End
Unit
Notes
V
CC
P Full FMB Primary V
CC
Socketed VRM Primary V
CC
2.4
3.1
3.5
3.5
V
V
5% tolerance
over range
V
CC
S FMB Secondary V
CC
3.3
3.3
V
5% tolerance
V
CC
5 FMB 5 V V
CC
5.0
5.0
V
5% tolerance
P
Max
FMB Thermal Design power
45
W
I
CCP
Full FMB V
CC
P Current 0.3
14.5
A
I
CCS
FMB V
CC
S Current 0
3.0
A
I
CC5
FMB V
CC
5 Current
340
mA
C
P
High Frequency V
CC
P
Decoupling
40
µF
40 1 µF 1206
packages
C
S
High Frequency V
CC
S
Decoupling
10
µF
10 1 µF 1206
packages
T
C
FMB Operating Case
Temperature
85
°C
NOTE:
1. Values are preliminary, per processor, and are not tested parameters. They are solely recommendations.
4.0 GTL+ Interface Specification
This section defines the new open-drain bus called
GTL+. The primary target audience is designers
developing systems using GTL+ devices such as the
Pentium Pro processor and the 82450 PCIset. This
specification will also be useful for I/O buffer
designers developing an I/O cell and package to be
used on a GTL+ bus.
This specification is an enhancement to the GTL
specification. The enhancements were made to allow
the interconnect of up to eight devices operating at
66.6 MHz and higher using manufacturing techniques
that are standard in the microprocessor industry. The
specification enhancements over standard GTL
provide better noise margins and reduced ringing.
Since this specification is different from the GTL
specification, it is referred to as GTL+.
The GTL+ specification defines an open-drain bus
with external pull-up resistors providing termination to
a termination voltage (V
TT
). The specification
includes a maximum driver output low voltage (V
OL
)
value, output driver edge rate requirements, example
AC timings, maximum bus agent loading
(capacitance and package stub length), and a
receiver threshold (V
REF
) that is proportional to the
termination voltage.
The specification is given in two parts. The first, is
the system specification which describes the system
environment. The second, is the actual I/O
specification, which describes the AC and DC
characteristics for an I/O transceiver.
Note that some of the critical distances, such as
routing length, are given in electrical length (time)
instead of physical length (distance). This is because
the system design is dependent on the propagation
time of the signal on a printed circuit board trace
rather than just the length of the trace. Different PCB
materials, package materials and system
construction result in different signal propagation
velocities. Therefore, a given physical length does
not correspond to a fixed electrical length. The
distance (time) calculation up to the designer.