Systems, Inc.
133MHz Clock Generator and Integrated Buffer for PowerPC鈩?/div>
General Description
The
ICS9341
generates all clocks required for high speed
PowerPC RISC microprocessor systems. Generating clocks in
phase with an external reference frequency.
Spread Spectrum may be enabled by driving the SS_EN pin
active. Spread spectrum typically reduces system EMI by 8dB
to 10dB. This simplifies EMI qualification without resorting to
board design iterations or costly shielding. The
ICS9341
employs a proprietary closed loop design, which tightly
controls the percentage of spreading over process and
temperature variations.
Features
Generates the following system clocks:
- 4-CPUA (3.3V, up to 133MHz)
- 4-CPUB (3.3V, up to 133MHz)
- 8-PCI (3.3V, 33.3MHz)
- 1-OUT (3.3v, 64MHz)
- 1-OUT/2 (3.3V, OUT/2MHz)
- 2-REF (3.3V, 14.318MHz)
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Up to 133MHz frequency support.
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Stop clocks for power management
Spread Spectrum for EMI control
鹵.25% center spread
Skew characteristics:
- CPU - CPU: <350ps
- CPU - PCI: <500ps
- PCI - PCI: <500ps
Block Diagram
X1
X2
OSC
/4
2
4
REF (0:1)
CPUCLKA (1:4)
/2
PLL
Spread
Spectrum
C
o
n
t
r
o
l
Pin Configuration
GNDREF
X1
X2
VDDPCI
PCICLK1
PCICLK2
PCICLK3
PCICLK4
GNDPCI
GNDCPUB
CPUB1
CPUB2
CPUB3
CPUB4
VDDCPUB
VDDPCI
PCICLK5
PCICLK6
PCICLK7
PCICLK8
FS0
FS1
*OUT_SEL0
GNDPCI
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
REF1
REF0
VDDREF
CPUA1
CPUA2
SS_EN
GNDCPUA
OUT_SEL1*
PD#
VDDCPUA
CPUA3
CPUA4
CPUB_STOP#**
VDDD
VDDOUT
OUT
OUT/2
GNDOUT
GNDA
GNDD
N/C
N/C
*PCI_STOP#
VDDA
STOP
4
CPUCLKB (1:4)
CPUB_STOP#
OUT_SEL (0:1)
PCI_STOP#
SS_EN
/3
PLL2
/6
/5
/2
PD#
OUT/2
/4
/5
/6
/8
STOP
8
PCICLK (1:8)
Power Groups:
VDDREF, GNDREF = REF, X1, X2
GNDPCI, VDDPCI = PCICLK
VDD66, GND66 = 3V66
VDD48, GND48 = 48MHz
VDDCOR, GNDCOR = PLL Core
VDDLCPU/2 , GNDLCPU/2 = CPU/2
VDDLIOAPIC, GNDIOAPIC = IOAPIC
48-pin SSOP
* Internal pull-up resistor of 120K to 3.3V on
indicated inputs
** Internal pull-down resistor of 120K to GND
on indicated inputs.
9341 Rev A 10/12/99
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.
ICS9341
OUT
1
2
3
4
5
6
7
8
9
