PI6C100 Datasheet, PDF (1/13 Pages) Pericom Semiconductor Corporation – Precision Clock Synthesizer for Desktop PC’s

PI6C100
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Precision Clock Synthesizer
for Desktop PC’s
Features
Description
• Four copies of CPU clock with V_DD of 2.5V + 5%
• 100 MHz or 66 MHz operation
• Eight copies of PCI clock, (synchronous with CPU clock) 3.3V
• Two copies of IO APIC clock @14.31818 MHz
• Two copies of 48 MHz clock
• Three copies of Ref. clock @14.31818 MHz (3.3V TTL)
• Low cost 14.31818 MHz crystal oscillator input
The PI6C100 is a high-speed low-noise clock generator designed to
work with the PI6C180 clock buffer to meet all clock needs for Intel
Architecture platforms. CPU and chipset clock frequencies of 66.6
MHz and 100 MHz are supported.
Split supplies of 3.3V and 2.5V are used. The 3.3V power supply
powers a portion of the I/O and the core. The 2.5V is used to power
the remaining outputs. 2.5V signaling follows JEDEC standard
8-X. Power sequencing of the 3.3V and 2.5V supplies is not required.
• Spread spectrum modulation of CPU and PCI clocks for
reduced EMI
• Power management control
An asynchronous PWRDWN# signal may be used to orderly power
down (or up) the system.
• Isolated core V_DD, V_SS pins for noise reduction
• 48-pin SSOP package (V48)
Block Diagram
XTAL_IN
XTAL_OUT
SEL0,1
SPREAD#
SEL100/66#
REF
OSC
PLL1
PLL2
*KBBAHI
VDDREF
VDDAPIC
VDDCPU 0,1
CPUSTOP#
÷2 VDDPCI 0,1
PCISTOP#
3 _REF[0:2]
2 _APIC0,1
4 _CPUCLK[0:3]
7 _PCICLK[1:7]
PCICLK_F
VDD48MHz
2 _48MHz
Pin Configuration
REF0
REF1
V_SSREF
XTAL_IN
XTAL_OUT
V_SSPCI0
PCICLK_F
PCICLK1
V_DDPCI0
PCICLK2
PCICLK3
V_SSPCI1
PCICLK4
PCICLK5
V_DDPCI1
PCICLK6
PCICLK7
V_SSPCI2
VDDCORE0
V_SSCORE0
V_DD48MHz
48MHz
48MHz
V_SS48MHz
1
48
2
47
3
46
4
45
5
44
6
43
7
42
8
41
9 48-Pin 40
10 _V48 39
11
38
12
37
13
36
14
35
15
34
16
33
17
32
18
31
19
30
20
29
21
28
22
27
23
26
24
25
VDDREF
REF2
V_DDAPIC
APIC0
APIC1
V_SSAPIC
NC
VDDCPU0
CPUCLK0
CPUCLK1
V_SSCPU0
V_DDCPU1
CPUCLK2
CPUCLK3
V_SSCPU1
V_DDCORE1
V_SSCORE1
PCISTOP#
CPUSTOP#
PWRDWN#
SPREAD#
SEL0
SEL1
SEL100/66#
198
PS8142A 10/13/98