W149
11
SDRAM Clock Outputs, SDRAM, SDRAM0:11 (Lump Capacitance Test Load = 30 pF)
Parameter
Description
Test Condition/Comments
CPU = 66.6 MHz
CPU = 100 MHz
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
tP
Period
Measured on rising edge at 1.5V
30
30
ns
tH
High Time
Duration of clock cycle above 2.4V,
at min. sdge rate (1.5 V/ns)
5.6
3.3
ns
tL
Low Time
Duration of clock cycle below 0.4V,
at min. sdge rate (1.5 V/ns)
5.3
3.1
ns
tR
Output Rise Edge
Rate
Measured from 0.4V to 2.4V
1.5
4
1.5
4
V/ns
tF
Output Fall Edge
Rate
Measured from 2.4V to 0.4V
1.5
4
1.5
4
V/ns
tPLH
Prop Delay LH
Input edge rate faster than 1 V/ns
1
5
1
5
ns
tPHL
Prop Delay HL
Input edge rate faster than 1 V/ns
1
5
1
5
ns
tD
Duty Cycle
Measured on rising and falling
edge at 1.5V, at min. sdge rate
(1.5 V/ns)
45
55
45
55
%
tJC
Jitter, Cycle-to-Cycle
Measured on rising edge at 1.5V.
Maximum difference of cycle time
between two adjacent cycles.
250
250
ps
tSK
Output Skew
Measured on rising edge at 1.5V
250
250
ps
tO
CPU to PCI Clock
Skew
Covers all CPU/PCI outputs. Mea-
sured on rising edge at 1.5V. CPU
leads PCI output.
1.5
4
1.5
4
ns
fST
Frequency
Stabilization from
Power-up (cold start)
Assumes full supply voltage
reached within 1 ms from
power-up. Short cycles exist prior
to frequency stabilization.
33
ms
Zo
AC Output
Impedance
Average value during switching
transition. Used for determining
series termination value.
30
30
Ω