Networking/PCI Clock Generator
MDS 1493-02A C
3
Revision 020204
Integrated Circuit Systems, Inc.
● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
MK1493-02A
Pin Descriptions
Pin
Name
Pin
Type
Pin Description
1
VDDAND
Power
Analog and digital power supply 3.3 V.
2
X1/CLK
XI
Crystal connection/input clock. Connect to a 25 MHz fundamental mode crystal.
3
X2
XO
Connect to a 25 MHz fundamental mode crystal or leave unconnected if X1 is a
4
REF2_50M
Output
REF2 or 50 MHz output.
5
VDDREF
Power
Power supply for REF outputs.
6
VSSREF
Power
Ground for REF outputs.
7
FREQSEL_REF0
I/O
Input frequency select input pin for 50 MHz/ REF2 (0=50 MHz select, 1=REF2
select). Output - REF0.( Internal Pull up resistor of 120K ohms see for page 21)
8
REF1
Output
REF1 clock output.
9
SCL
I/O
Clock pin for SMBUS circuitry. 5 V tolerant.
10
SDA
Input
Data pin for SMBUS circuitry. 5 V tolerant.
11
PCI_XSTPB
Input
Asynchronous input Stops all PCI_XCLK at logic level 0 when pulled low.( Internal
pull up resistor 120K)
12
CUP_STPB
Input
Asynchronous input halts CPU , DDR and PCI clocks at logic O when driven low. S.
(Internal pull up resistor 120K see page 21)
13
PCI0
Output
PCI Output clock 0.
14
PCI1
Output
PCI Output clock 1.
15
PCI2
Output
PCI Output clock 2.
16
PCI3
Input
PCI Output clock 3.
17
VDDPCI1
Power
Power supply for PCI clocks.
18
VSSPCI1
Power
Ground supply for PCI clocks.
19
VSSPCI_X2
Power
Ground for PCI_X clocks.
20
VDDPCI_X2
Power
Power supply for PCI_X clocks.
21
FS0_PCI_X0
I/O
FS0 input/PCI_X0 output. (Internal Pull Down resistor 120K , see page 21).
22
FS1_PCI-X1
I/O
FS1 input/PCI_X1 output. (Internal Pull Down resistor 120K , see page 21)
23
FS2_PCI_X2
I/O
FS2 input/PCI_X2 output. (Internal Pull Down resistor 120K , see page 21).
24
FS3_PCI_X3
I/O
FS3 input/PCI_X3 output. (Internal Pull up resistor 120K , see page 21).
25
SSEN_PCI4
I/O
Spread spectrum enable (0=SS disabled, 1=enabled). PCI clock output. (Internal pull
down resistor 120K see page 21)
26
PCI_X5
Output
PCI_X clock output.
27
PCI_X6
Output
PCI_X clock output.
28
VSSPCI_X1
Power
Ground for PCI clocks.
29
VDDPCI_X1
Power
Power supply for PCI clocks.
30
DDRC5
Output
Complementary clock output of DDRT5.
31
DDRT5
Output
True clock output of DDRT5.
32
DDRC4
Output
Complementary clock output of DDRT4.
33
DDRT4
Output
True clock output of DDRT4.
34
VSSDR2
Power
Ground for DDR clocks.
35
VDDDR2
Power
Power supply for DDR clocks (2.5 V only for complementary outputs).
36
DDRC3
Output
Complementary clock output of DDRT3.