IMISC481D
SYSTEM CLOCK CHIP
May 29, 1996
CMOS LSI
PLL FREQUENCY SYNTHESIZER
FREQUENCY TABLE
PRODUCT FEATURES
S2
S1
S0
CPU
PCI
Supports Pentium™ system boards with onboard
audio peripherals
0
0
0
55
27.6
0
0
1
66.6
33.3
Supports synch/semisynchronous PCI bus
0
1
0
50
25
Operates from 5V or 3.3V supply
0
1
1
60
30
Separate CPU clock buffer VDD supports mixed
5V/3.3V outputs
1
0
0
50
33.3*
1
0
1
EXT
EXT/2
1
1
0
TS
TS
1
1
1
SL
SL
60 mA buffer switching current
Tristate, synch stop clock, and power down modes
*Operates only at VDD = 5V
34 Pin SSOP package for minimum board space
AUDIO/PERIPHERAL CLOCKS
S4
0
0
1
1
S3
0
1
0
1
F1
14.3
14.3
48
14.3
F2
12.28
11.28
24
8.19
F3
40
40
40
40
BLOCK DIAGRAM
XI
2
OSC
14.3 MHz
XO
CPU VDD
S0, 1, 2
LF
3
PLL
1
B
5
CPU
6
S4
F2
F1
VSS
F3
CPU1
CPU2
CPU3
CPUVDD
CPU4
CPU5
VDD
AVSS
LF1
LF2
LF3
AVDD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
14.3MHz/EXT
VDD
XOUT
XIN
VSS
PCI6
PCI5
PCI4
14.3 MHz
PCI3
PCI2
PCI1
VDD
S0
S1
S2
S3
PCI
B
2
LF
F1
2
S3, 4
F2
PLLS
F3
1
1
2
AUDIO/SIO/KBRD
3
AVDD
AGRD
CONNECTION DIAGRAM
VDD
VSS
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035 TEL: 408-263-6300 ext. 275 FAX 408-263-6571
Rev. 1.0
APPLICATIONS
Pentium™ Systems with multimedia audio capability
integrated on the system board.
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