cy2256 Cypress Semiconductor Corporation., cy2256 Datasheet - Page 4

• Manufacturer Part Number: cy2256
• Description: Pentium Cyrix 6x86 Compatible Clock Synthesizer/driver Opti Viper Chipset
• Manufacturer: Cypress Semiconductor Corporation.

]
Switching Characteristics
Duty Cycle Timing
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
Notes:
Switching Waveforms
Parameter
1
1C
1C
1D
1D
2
3
4
2
2
5
6
7
8
9
10
4.
5.
6.
7.
All parameters specified with outputs fully loaded.
Duty cycle is measured at 1.5V.
A LOW and HIGH time of 12 ns corresponds to a PCICLK frequency of 33.33 MHz. For PCICLK frequencies of 30 MHz and 25 MHz, the LOW and HIGH
times are each respectively 13.33 ns and 16 ns.
Synchronous mode only
All
CPUCLKA/B
PCICLK
CPUCLKA/B
PCICLK
CPUCLKA/B
CPUCLKA/B
CPUCLKA/B
PCICLK
REFCLK
CPUCLKA
PCICLK
CPUCLKA/B,
PCICLK
CPUCLKA/B
CPUCLKA/B
PCICLK
1.5V
Output
t
1A
1.5V
[4]
Output Duty Cycle
CPU Clock HIGH Time
PCI Clock HIGH Time
CPU Clock LOW Time
PCI Clock LOW Time
CPU Clock Rising and Fall-
ing Edge Rate
CPU Clock Rise Time
CPU Clock Fall Time
PCI Clock Rising and Fall-
ing Edge Rate
Reference Clock Rising
and Falling Edge Rate
CPU-CPU Clock Skew
PCI-PCI Clock Skew
CPU-PCI Clock Skew
Cycle-Cycle Clock Jitter
Power-up Time
Power-up Time
t
1B
Description
1.5V
[5]
[6]
[7]
[6]
[7]
2256–3
4
t
Measured at 2.4V
Measured at 2.4V
Measured at 0.4V
Measured at 0.4V
Measured between 0.4V and 2.4V
Measured between 0.4V and 2.4V
Measured between 2.4V and 0.4V
Measured between 0.4V and 2.4V
Measured between 0.4V and 2.4V
Measured at 1.5V
Measured at 1.5V
Measured at 1.5V
CPU Clock jitter
CPU clock stabilization from
power-up
PCI clock stabilization from
power-up
1
= t
1A
t
Test Conditions
1B
Min.
45%
12.0
12.0
5.0
5.0
0.5
0.5
0.5
1
1
Max.
55%
200
200
500
250
4.0
2.0
2.0
CY2256
4
3
3
Unit
V/ns
V/ns
V/ns
ms
ms
ns
ns
ns
ns
ns
ns
ps
ps
ps
ps