
PRELIMINARY
157
A
PCIset Electrical Specifications
1.5
AC Specifications
The following tables list the AC specifications associated with the Intel 450GX PCIsets. Care should be taken to
read any notes associated with each parameter listed.
Table 10, contains AC specifications for the CMOS signals. Please note that the PCI signals are specified with
reference to the PCLKIN; the testability signals are specified with reference to the TCK, and all other signals
reference the system bus clock, BCLK
1. Measured at rising edge of BCLK crossing 1.5V.
2. Please refer to the PCI Specification 2.0 for more details.
1. Values correspond to input waveforms as specified in the GTL+ Interface Specification in Pentium Pro Processor Developer’s
Manual: Specifications. A waveform with less than 200mV of overdrive is acceptable if it meets the criteria in Figure 5. How-
ever, in this case, the minimum setup specification will be impacted by 1ns, making Setup Min 5.5ns. An example of a signal
that would benefit from this derating is shown in Figure 6.
2. Outputs measured into 25
tied to 1.5V. Measurement made at 1.0V crossing.
Table 8. AC Specifications (Clock signal groups)
Symbol
Parameter
Min
Max
Unit
Figure
Notes
f
BCLK Frequency
50.00
66.67
MHz
T1
BCLK Period
15
20
ns
2.2
T2
BCLK Period Stability
300
ps
(1)
T3
BCLK High Time
6
ns
2.2
At > 2.0V
T4
BCLK Low Time
6
ns
2.2
At < 0.8V
T5
BCLK Rise Time
0.3
1.5
ns
2.2
0.8-2.0V
T6
BCLK Fall Time
0.3
1.5
ns
2.2
2.0-0.8V
T7
PCLKIN Period
30
ns
(2)
T44
TCK Rise/Fall Time
0
50
ns
T44a
TCK Frequency
16
MHz
Table 9. AC Specifications (GTL+ Signals)
Symbol
Parameter
Setup Min
Hold Min
Delay Min
Delay Max
Unit
Notes
T8
GTL+ Inputs
4.5
0.3
ns
(1)
T9
GTL+ Outputs
1.0
6.0
ns
(2)
T10
GTL+ I/O
4.5
0.3
1.0
6.0
ns
(1) (2)