ics9248-127 ETC-unknow, ics9248-127 Datasheet

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ics9248-127

Manufacturer Part Number
ics9248-127
Description
Frequency Generator Integrated Buffers Pentium/protm
Manufacturer
ETC-unknow
Datasheet
General Description
The ICS9248-127 is the single chip clock solution for Desktop
designs using the VIA MVP4 and Aladdin 7 style chipset. It
provides all necessary clock signals for such a system.
Spread spectrum may be enabled through I
Spread spectrum typically reduces system EMI by 8dB to
10dB. This simplifies EMI qualification without resorting to
board design iterations or costly shielding. The ICS9248-
127 employs a proprietary closed loop design, which tightly
controls the percentage of spreading over process and
temperature variations.
Block Diagram
Frequency Generator & Integrated Buffers for PENTIUM/Pro
CLK_STOP#
Power Groups
VDDCPU, GNDCPU = CPUCLKS, CPUCLK_F
VDDSDR, GNDSDR = SDRAMCLKS, SDRAM_F
VDDPCI, GNDPCI = PCICLKS, PCICLK_F
VDD48 = 48MHz, 24MHz
VDDREF, GNDREF = REF, X1, X2
PCI_STOP#
BUFFER IN
9248-127 Rev C 8/18/00
FS(3:0)
MODE
SDATA
SCLK
X2
X1
4
XTAL
OSC
Spectrum
PLL2
Spread
POR
Integrated
Circuit
Systems, Inc.
PLL1
Config.
Control
LATCH
Reg.
Logic
4
/ 2
DIVDER
CLOCK
PCI
STOP
STOP
STOP
2
C programming.
12
2
3
5
48MHz
24MHz
CPUCLK_F
CPUCLK (2:0)
SDRAM (11:0)
SDRAM_F
PCICLK (4:0)
PCICLK_F
REF (1:0)
Features
Up to 124MHz frequency support.
Spread Spectrum for EMI control 0 to -0.5% down
spread and ±0.25% center spread
Serial I
Frequency Select, Spread Spectrum.
Provides the following system clocks
- 4-CPUs @ 3.3V, up to 124MHz.
- 13-SDRAMs @3.3V, up to 124MHz
- 6-PCI (including 1 free running, PCICLK_F)
- 1-24MHz @3.3V fixed.
- 1-48MHz @3.3V fixed.
- 2-REF @3.3V, 14.318MHz.
Efficient Power management scheme through PCI
and STOP CLOCKS.
@3.3V, CPU/2 or CPU/3.
(including SDRAM_F)
*PCI_STOP#/REF0
*MODE/PCICLK_F
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.
* Internal Pull-up Resistor of 240K to VDD
*FS3/PCICLK0
BUFFER IN
2
SDRAM11
SDRAM10
C interface for Power Management,
PCICLK1
PCICLK2
PCICLK3
PCICLK4
VDDSDR
SDRAM9
SDRAM8
VDDREF
VDDPCI
VDDPCI
SDATA
SCLK
GND
GND
GND
GND
Pin Configuration
X1
X2
48-Pin SSOP
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
1
2
3
4
5
6
7
8
9
Pentium is a trademark of Intel Corporation
I
2
C is a trademark of Philips Corporation
ICS9248-127
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/FS2*
VDDCPU
CPUCLK_F
CPUCLK0
GND
CPUCLK1
CPUCLK2
CLK_STOP#
GND
SDRAM_F
SDRAM0
SDRAM1
VDDSDR
SDRAM2
SDRAM3
GND
SDRAM4
SDRAM5
VDDSDR
SDRAM6
SDRAM7
VDD48
48MHz/FS0*
24MHz/FS1*
TM

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ics9248-127 Summary of contents

Page 1

... Systems, Inc. Frequency Generator & Integrated Buffers for PENTIUM/Pro General Description The ICS9248-127 is the single chip clock solution for Desktop designs using the VIA MVP4 and Aladdin 7 style chipset. It provides all necessary clock signals for such a system. Spread spectrum may be enabled through I Spread spectrum typically reduces system EMI by 8dB to 10dB ...

Page 2

... ICS9248-127 Pin Descriptions ...

Page 3

... ICS9248-127 ...

Page 4

... ICS9248-127 Serial Configuration Command Bitmap Byte0: Functionality and Frequency Select Register (default = ± ...

Page 5

... ICS9248-127 ...

Page 6

... ICS9248-127 Byte 4: Reserved Active/Inactive Register (1 = enable disable ...

Page 7

... V +/-5% (unless otherwise stated) CONDITIONS pF; Select @ 66M 3 Logic Inputs X1 & X2 pins To 1st crossing of target Freq. From 1st crossing to 1% target Freq. From target Freq 1 ICS9248-127 +0 TYP MAX -0.3 0 180 14.318 5 27 ...

Page 8

... ICS9248-127 Electrical Characteristics - CPU 70C; VDD=3.3V +/-5 ETER SYM BOL 1 Output Impedance Output Impedance Output High Voltage Output Low Voltage Output High Current Output Low Current ...

Page 9

... 0 0 2.4 V r2A 2 0.4 V f2A 1.5 V t2A 1.5 V sk2A 1.5 V sk2A T ICS9248-127 MIN TYP MAX UNITS 2.4 2.9 V 0.2 0.4 V -58 - 1.38 2.0 ns 1. 236 500 ps 214 ...

Page 10

... ICS9248-127 General I The information in this section assumes familiarity with I For more information, contact ICS for an I How to Write: How to Write: Controller (Host) ICS (Slave/Receiver) Start Bit Address D2 (H) Dummy Command Code Dummy Byte Count Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Stop Bit 1 ...

Page 11

... Shared Pin Operation - Input/Output Pins Programming Header Via to Gnd Device Pad Via to VDD 2K 8.2K Clock trace to load Series Term. Res. Fig. 1 ICS9248-127 ...

Page 12

... CLK_STOP asychronous input to the clock synthesizer used to turn off the CPU clocks for low power operation. CLK_STOP# is synchronized by the ICS9248-127. The minimum that the CPU clock is enabled (CPU_STOP# high pulse) is 100 CPU clocks. All other clocks will continue to run while the CPU clocks are disabled. The CPU clocks will always be stopped in a low state and start in such a manner that guarantees the high pulse width is a full pulse ...

Page 13

... PCI_STOP# Timing Diagram PCI_STOP asynchronous input to the ICS9248-127 used to turn off the PCICLK [4:0] clocks for low power operation. PCI_STOP# is synchronized by the ICS9248-127 internally. The minimum that the PCICLK [4:0] clocks are enabled (PCI_STOP# high pulse least 10 PCICLK [4:0] clocks. PCICLK [4:0] clocks are stopped in a low state and started with a full high pulse width guaranteed ...

Page 14

... ICS9248-127 Ordering Information ICS9248yF-127-T Example: ICS XXXX PPP - T Designation for tape and reel packaging Pattern Number ( digit number for parts with ROM code patterns) Package Type Revision Designator (will not correlate with datasheet revision) Device Type (consists digit numbers) ...

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