ICST AV9148BF-04, ICS9148BF-04 Datasheet

Integrated
Circuit
Systems, Inc.

General Description Features

ICS9148B-04

Block Diagram

Pentium is a trademark of Intel Corporation
I

2

C is a trademark of Philips Corporation

Frequency Generator & Integrated Buffers for PENTIUM/Pro

TM

9148-04 Rev B 01/20/98

Pin Configuration

 3.3V outputs: SDRAM, PCI, REF, 48/24MHz
 2.5V or 3.3V outputs: CPU, IOAPIC
 20 ohm CPU clock output impedance
 20 ohm PCI clock output impedance
 Skew from CPU (earlier) to PCI clock - 1 to 4 ns, center

2.6 ns.

 No external load cap for C

L

=18pF crystals
 ±250 ps CPU, PCI clock skew
 400ps (cycle to cycle) CPU jitter
 Smooth frequency switch, with selections from 50 to 83.3

MHz CPU.

I

2

C interface for programming
 2ms power up clock stable time
 Clock duty cycle 45-55%.
 48 pin 300 mil SSOP package
 3.3V operation, 5V tolerant input.

48-Pin SSOP

Power Groups

VDD1 = REF (0:1), X1, X2
VDD2 = PCICLK_F, PCICLK(0:5)
VDD3 = SDRAM (0:11), supply for PLL core,
24MHz, 48MHz
VDDL1 = IOAPIC
VDDL2 = CPUCLK (0:3)

* Internal Pull-up Resistor of
240K to 3.3V on indicated inputs

The ICS9148B-04 generates all clocks required for high
speed RISC or CISC microprocessor systems such as Intel
PentiumPro or Cyrix. Eight different reference frequency
multiplying factors are externally selectable with smooth
frequency transitions.

Features include four CPU, seven PCI and Twelve SDRAM
clocks. Two reference outputs are available equal to the
crystal frequency. Plus the IOAPIC output powered by VDDL1.
One 48 MHz for USB, and one 24 MHz clock for Super IO.
Spread Spectrum built in - ±1.5% modulation to reduce the
EMI. Serial programming I

2

C interface allows changing
functions, stop clock programing and Frequency selection.
Rise time adjustment for VDD at 3.3V or 2.5V CPU.
Additionally, the device meets the Pentium power-up
stabilization, which requires that CPU and PCI clocks be
stable within 2ms after power-up. It is not recommended to
use I/O dual function pin for the slots (ISA, PCI, CPU, DIMM).
The add on card might have a pull up or pull down.

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.

2

ICS9148B-04

Pin Descriptions

Notes:

1: Internal Pull-up Resistor of 240K to 3.3V on indicated inputs
2: Bidirectional input/output pins, input logic levels are latched at internal power-on-reset. Use 10Kohm resistor to

program logic Hi to VDD or GND for logic low.

PIN NUMBER PIN NAME TYPE DESCRIPTION

1 VDD1 PW R Ref (0:1), XTAL power supply, nominal 3.3V
2

REF0 OUT 14.318 MHz reference clock.
CPU3.3#_2.5

1,2

IN

Indicates whether VDDL2 is 3.3V or 2.5V. High=2.5V CPU,
LOW=3.3V CPU

1

. Latched input

2

3,9,16,22,27,

33,39,45

GND PWR Ground

4X1 IN

Crystal input, has internal load cap (33pF) and feedba ck
resistor from X2

5X2 OUT

Crystal output, nominally 14.318MHz. Has internal load
cap (33pF)

6,14 VDD2 PW R Supply for PCICLK_F and PCICLK (0:5), nominal 3.3V

7

PCICLK_F

OUT

Free running PCI clock

FS1

1, 2

IN

Frequency select pin. Latched Input

8

PCICLK0

OUT

PCI clock output.

FS2

1, 2

IN

Frequency select pin. Latched Input

10, 11, 12, 13

PCICLK(1:4)

OUT

PCI clock outputs.

15

PCICLK5

OUT

PCI clock output. (In desktop mode, MODE=1)

PCI_STOP#

1

IN

Halts PCICLK(0:5) clocks at logic 0 level, w hen input low (In
mobile mode, MODE=0)

17, 18, 20, 21,

28, 29, 3 1, 32,

34, 35,37,38

SDRAM (0:11)

OUT

SDRAM clock outputs.

19,30,36

VDD3

PWR

Supply for SDRAM (0:11), PLL Core and 24, 48MHz clocks,
nominal 3.3V.

23

SDATA

IN

Data input for I2C serial input.

24

SCLK

IN

Clock input of I2C input

25

24MHz

OUT

24MHz output clock

MODE

1, 2

IN

Pin 15, pin 46 function select pin, 1= Desktop Mode, 0=Mobile M ode.
Latched Input.

26

48MHz

OUT

48MHz output clock

FS0

1, 2

IN

Frequency select pin. Latched Input

40, 41, 43, 44

CPUCLK(0:3)

OUT

CPU clock outputs, powered by VDDL2. Low if CPU_STOP#=Low

42

VDDL2

PWR

Supply for CPU (0:3), either 2.5V or 3.3V nominal

46

REF1 OUT

14.318 MHz reference clock , (in Desktop Mode, MODE =1) This
REF output is the STRONGER buffer for ISA BUS loads.

CPU_STOP#

1

IN

Halts CPUCLK (0:3) clocks at logic 0 level, when input low (in
Mobile Mode, MODE= 0)

47 IOAPIC OUT IOAPIC clock output. 14.318 MHz Powered by VDDL1.
48 VD DL 1 P W R Supply for IOAPIC, either 2.5 or 3.3V nominal

3

ICS9148B-04

Functionality

VDD1,2,3 = 3.3V±5%, V

DDL

1,2 = 2.5V±5% or 3.3±5%, TA=0 to 70°C

Crystal (X1, X2) = 14.31818MHz

CPU3.3#_2.5

Input level

(Latch ed Data )

Buffer Selected for

operation at:

12.5V VDD

03.3V VDD

CPU 3.3#_2.5V Buffer selector for CPUCLK and IOAPIC drivers.

Power Management Functionality

FS2 FS1 FS0

CPU,

SDRAM(MHz)

PCICLK

(MHz)

REF, IOAPIC

(MHz)
0 0 0 50.0 25.0 (1/2 CPU) 14.318
0 0 1 75.0 32 14.318
0 1 0 83.3 41.65 (1/2 CPU) 14.318
0 1 1 68.5 34.25 (1/2 CPU) 14.318
1 0 0 83.3 33.3 14.318
1 0 1 75.0 37.5 (1/2 CPU) 14.318
1 1 0 60.0 30.0 (1/2 CPU) 14.318
1 1 1 66.8 33.4 (1/2 CPU) 14.318

Mode Pin - Power Management Input Control

MODE, Pin 25
(Latched Input)

Pin 46 Pin 15

0

CPU_STOP#

(INPUT)

PCI_STOP#

(INPUT)

1

REF1

(OUTPUT)

PCICLK5

(OUTPUT)

CPU_STOP# PCI_S TOP#

CPUCLK

Outputs

PCICLK

(0:5)

PCICLK_F,

REF,

24/48MHz

and SDRAM

Crystal

OSC

VCO

0 1 Stopp ed Low Running Running Running Running
1 1 Running Running Running Running Running
1 0 Running Stopped Low Running Running Running

4

ICS9148B-04

Byte0: Functionality and Frequency Select Register (default = 0)

Serial Configuration Command Bitmap

I2C is a trademark of Philips Corporation

Bit Description PWD

Bit 7

0 - ±1.5% Spread Spectr um Modulation
1 - ±0.5% Spread Spectr um Modulation

0

Bit 6:4

Bit6 Bit5 Bit4

111
110
101
100
011
010
001
000

CPU clock

66.8

60.0

75.0

83.3

68.5

83.3

75.0

50.0

PCI

33.4(1/2 CPU)

30.0 (1/2 CPU)

37.5 (1/2 CPU )

33.3

34.5 (1/2 CPU )

41.65 (1/2 CPU)

32.0

25.0 (1/2 CPU )

Note 1

Bit 3

0 - Frequency is selected b y hardware select,
Latched Inputs
1 - Frequency is selected by Bit 6:4 (above)

0

Bit 2

0 - Spread Spectrum center sp read type.
1 - Spread Spectrum down spread type.

0

Bit 1

0 - Normal
1 - Spread Spectrum Enabled

0

Bit 0

0 - Running
1- Tristate all outputs

0

A. For the clock generator to be addressed by an I2C controller, the following address must be sent as a start sequence, with

an acknowledge bit between each byte.

B. The clock generator is a slave/receiver I2C component. It can "read back "(in Philips I2C protocol) the data stored in the

latches for verification. (set R/W# to 1 above). There is no BYTE count supported, so it does not meet the Intel SMB
PIIX4 protocol.

C. The data transfer rate supported by this clock generator is 100K bits/sec (standard mode)

D. The input is operating at 3.3V logic levels.

E. The data byte format is 8 bit bytes.

F. To simplify the clock generator I2C interface, the protocol is set to use only block writes from the controller. The bytes

must be accessed in sequential order from lowest to highest byte with the ability to stop after any complete byte has
been transferred. The Command code and Byte count shown above must be sent, but the data is ignored for those two
bytes. The data is loaded until a Stop sequence is issued.

G. In the power down mode (PWR_DWN# Low), the SDATA and SCLK pins are tristated and the internal data latches

maintain all prior programming information.

H. At power-on, all registers are set to a default condition. See Byte 0 detail for default condition, Bytes 1 through 5 default

to a 1 (Enabled output state)

Then Byte 0, 1, 2, etc in
sequence until STOP.

Byte 0, 1, 2, etc in sequence until STOP.

Clock Generator

Address (7 bits)

ACK

+ 8 bits dummy

command code

ACK

+ 8 bits dummy

Byte count

ACK

A(6:0) & R/W#

D2

(H)

Clock Generator

Address (7 bits)

ACK

Byte 0 ACK Byte 1 ACK

A(6:0) & R/W#

D3

(H)

Note 1. Default at Power-up will be for latched logic

inputs to define frequency. Bits 4, 5, 6 are default
to 000, and if bit 3 is written to a 1 to use Bits
6:4, then these should be defined to desired
frequency at same write cycle.

Note: PWD = Power-Up Default

5

ICS9148B-04

Byte 1: CPU, Active/Inactive Register
(1 = enable, 0 = disable)

Byte 2: PCI Active/Inactive Register (1 = enable, 0 = disable)

Byte 3: SDRAM Active/Inactive Register
(1 = enable, 0 = disable)

Notes:

1. Inactive means outputs are held LOW and are disabled
from switching.

Notes:

1. Inactive means outputs are held LOW and are disabled
from switching.

2. PCICLK5 only in Desktop Mode

Notes:

1. Inactive means outputs are held LOW and are disabled
from switching.

Bit Pin # PWD Description

Bit 7 - 1 (Reserved)
Bit 6 - 1 (Reserved)
Bit 5 - 1 (Reserved)
Bit 4 - 1 (Reserved)
Bit 3 40 1 CPUCLK3 (Act/Inact)
Bit 2 41 1 CPUCLK2 (Act/Inact)
Bit 1 43 1 CPUCLK1 (Act/Inact)
Bit 0 44 1 CPUCLK0 (Act/Inact)

Bit Pin # PWD Description

Bit 7 - 1 (Reserved)
Bit 6 7 1 PCICLK_F (Act/Inact)

Bit 5 15 1

PCICLK5 (Act/Inact)

(Desktop on ly)
Bit 4 14 1 PCICLK4 (Act/Inact)
Bit 3 12 1 PCICLK3 (Act/Inact)
Bit 2 11 1 PCICLK2 (Act/Inact)
Bit 1 10 1 PCICLK1 (Act/Inact)
Bit 0 8 1 PCICLK0 (Act/Inact)

Bit Pin # PWD Description

Bit 7 28 1 SDRAM7 (Act/Inact)
Bit 6 29 1 SDRAM6 (Act/Inact)
Bit 5 31 1 SDRAM5 (Act/Inact)
Bit 4 32 1 SDRAM4 (Act/Inact)
Bit 3 34 1 SDRAM3 (Act/Inact)
Bit 2 35 1 SDRAM2 (Act/Inact)
Bit 1 37 1 SDRAM1 (Act/Inact)
Bit 0 38 1 SDRAM0 (Act/Inact)

Byte 4: SDRAM Active/Inactive Register
(1 = enable, 0 = disable)

Notes:

1. Inactive means outputs are held LOW and are disabled
from switching. These outputs are designed to be
configured at power-on and are not expected to be
configured during the normal modes of operation.

Bit Pin # PWD Description

Bit 7 - 1 ( Reserved)
Bit 6 - 1 ( Reserved)
Bit 5 - 1 ( Reserved)
Bit 4 - 1 ( Reserved)
Bit 3 17 1 SDRAM11 (Act/Inact)
Bit 2 18 1 SDRAM10 (Act /Inact)
Bit 1 20 1 SDRAM9 (Act/Inact)
Bit 0 21 1 SDRAM8 (Act/Inact)

Byte 5: Peripheral Active/Inactive Register
(1 = enable, 0 = disable)

Notes:

1. Inactive means outputs are held LOW and are disabled from
switching. These outputs are designed to be configured at
power-on and are not expected to be configured during the
normal modes of operation.

2. REF1 only in Desktop Mode

Bit Pin # PWD Description

Bit 7 - 1 ( Reserved)
Bit 6 - 1 ( Reserved)
Bit 5 - 1 ( Reserved)
Bit 4 47 1 IOAPIC (Act/Inact)
Bit 3 - 1 ( Reserved)
Bit 2 - 1 ( Reserved)
Bit 1 46 1 REF1 (Act/Inact)
Bit 0 2 1 REF0 (Act/Inact )

Bit Pin # PWD Description

Bit 7 - 1 (Reserved)
Bit 6 - 1 (Reserved)
Bit 5 - 1 (Reserved)
Bit 4 - 1 (Reserved)
Bit 3 - 1 (Reserved)
Bit 2 - 1 (Reserved)
Bit 1 - 1 (Reserved)
Bit 0 - 1 (Reserved)

Note: PWD = Power-Up Default

Byte 6: Optional Register For Possible Future Requirements

Notes:

1. Byte 6 is reserved by Integrated Circuit Systems for
future applications.