ICS9341 Datasheet, PDF (1/9 Pages) Integrated Circuit Systems – 133MHz Clock Generator and Integrated Buffer for PowerPC™

Integrated
Circuit
Systems, Inc.
ICS9341
133MHz Clock Generator and Integrated Buffer for PowerPC™
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.
Block Diagram
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)
• Up to 133MHz frequency support.
• Stop clocks for power management
• Spread Spectrum for EMI control
±.25% center spread
Skew characteristics:
- CPU - CPU: <350ps
- CPU - PCI: <500ps
- PCI - PCI: <500ps
X1
X2
OSC
CPUB_STOP#
OUT_SEL (0:1)
PCI_STOP#
SS_EN
PLL
Spread
Spectrum
C
o
n
t
r
PLL2
o
l
PD#
/4
/2
STOP
/3
/6
/5
/2
/4 /5 /6 /8
STOP
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
2 ^{REF (0:1)}
CPUCLKA (1:4)
4
CPUCLKB (1:4)
4
OUT
OUT/2
PCICLK (1:8)
8
Pin Configuration
GNDREF
1
X1
2
X2
3
VDDPCI
4
PCICLK1
5
PCICLK2
6
PCICLK3
7
PCICLK4
8
GNDPCI
9
GNDCPUB
10
CPUB1
11
CPUB2
12
CPUB3
13
CPUB4
14
VDDCPUB
15
VDDPCI
16
PCICLK5
17
PCICLK6
18
PCICLK7
19
PCICLK8
20
FS0
21
FS1
22
*OUT_SEL0
23
GNDPCI
24
48
REF1
47
REF0
46
VDDREF
45
CPUA1
44
CPUA2
43
SS_EN
42
GNDCPUA
41
OUT_SEL1*
40
PD#
39
VDDCPUA
38
CPUA3
37
CPUA4
36
CPUB_STOP#**
35
VDDD
34
VDDOUT
33
OUT
32
OUT/2
31
GNDOUT
30
GNDA
29
GNDD
28
N/C
27
N/C
26
*PCI_STOP#
25
VDDA
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.