CY2277A
Switching Characteristics (-1M, -7M, -12M)
[9, 10, 11]
Parameter
t
1
Output
CPUCLK
SDRAM
USBCLK
REF [0,1]
IOAPIC
PCI
CPUCLK,
IOAPIC
PCI
USBCLK,
REF0
SDRAM
REF1
CPUCLK
USBCLK
CPUCLK
USBCLK
CPUCLK
PCICLK
SDRAM
CPUCLK,
PCICLK
CPUCLK,
PCICLK
CPUCLK,
SDRAM
CPUCLK
SDRAM
PCICLK
USBCLK,
IOCLK
CPUCLK,
PCICLK,
SDRAM
CPU, PCI,
SDRAM
Description
Output Duty Cycle
[12]
Test Conditions
t
1
= t
1A
t
1B
Min.
45
Typ.
50
Max.
55
Unit
%
t
1
t
2
Output Duty Cycle
[12]
CPU and IOAPIC Clock
Rising and Falling Edge
Rate
PCI Clock Rising and
Falling Edge Rate
USB, REF0 Clock Rising
and Falling Edge Rate
SDRAM Rising and
Falling Edge Rate
REF1 Rising and Falling
Edge Rate
CPU Clock Rise Time
USB Clock Rise Time
CPU Clock Fall Time
USB Clock Fall Time
CPU-CPU Clock Skew
PCI-PCI Clock Skew
SDRAM-SDRAM Clock
Skew
CPU-PCI Clock Skew
-1M, -12M
CPU-PCI Clock Skew
-7M
CPU-SDRAM Clock
Skew
Cycle-Cycle Clock Jitter
Cycle-Cycle Clock Jitter
Cycle-Cycle Clock Jitter
Cycle-Cycle Clock Jitter
Power-up Time
t
1
= t
1A
t
1B
45
0.60
50
55
4.0
%
V/ns
Between 0.4V and 2.0V, V
DDCPU
= 2.5V
CPU clocks at 66.66 MHz
Between 0.4V and 2.0V, V
DDCPU
= 2.5V
Between 0.4V and 2.4V
Between 0.4V and 2.4V
SDRAM clocks at 66.66 MHz
Between 0.4V and 2.4V
Between 0.4V and 2.0V, V
DDCPU
= 2.5V
Between 0.4V and 2.0V
Between 2.0V and 0.4V, V
DDCPU
= 2.5V
Between 2.0V and 0.4V
Measured at 1.25V, V
DDCPU
= 2.5V
Measured at 1.5V
Measured at 1.5V
Measured at 1.25V for 2.5V clocks, and
at 1.5V for 3.3V clocks
Measured at 1.25V for 2.5V clocks, and
at 1.5V for 3.3V clocks
Measured at 1.25V for 2.5V clocks, and
at 1.5V for 3.3V clocks, V
DDCPU
= 2.5V
Measured at 1.25V for 2.5V clocks
Measured at 1.5V
Measured at 1.5V
Measured at 1.5V
CPU, PCI, and SDRAM clock stabili-
zation from power-up
Rate of change of frequency
t
2
t
2
t
2
t
2
t
3
t
3
t
4
t
4
t
5
t
5
t
5
t
6
t
6
t
7
t
8
t
8
t
8
t
8
t
9
0.65
0.65
0.70
0.5
0.4
0.4
100
4.0
4.0
4.0
2.0
2.4
2.5
2.4
2.5
250
400
300
V/ns
V/ns
V/ns
V/ns
ns
ns
ns
ns
ps
ps
ps
ns
ps
ps
ps
ps
ps
ps
ms
1.0
2.0
6.0
750
600
525
600
400
900
3
t
10
Frequency Slew Rate
2
MHz/
ms
Rev 1.0, November 25, 2006
Page 10 of 18