+/+…when timing is critical
C9837
Low EMI Clock Generator for Intel Mobile 133MHz/2 SO-DIMM Chipset Systems
Preliminary
Expanded Frequency Selection (MHz) 1,2
TEST
ESEL ESEL SEL
SEL
0
CPU
(0,1)
66.7
100
133.3
133.3
70
105
140
140
73.3
110
146.7
146.7
80
120
160
SDRAM
(0:3), DCLK
100*
3V66
(0:2)
66.6
66.6
66.6
66.6
70
70
70
70
73.3
73.3
73.3
73.3
80
80
80
80
PCI_F,
PCI(1:6)
33
Notes
#
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
10
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0% extension
(Default)
100*
133.3
100*
105*
105*
140
105*
110*
110*
146.7
110*
120*
120*
160
33
33
33
35
35
35
35
36.6
36.6
36.6
36.6
40
40
40
40
5% extension
10% extension
20% extension
160
120*
Note 1: Extended frequencies are only available via I2C interface. They are accessable via I2C Byte 5 bits 0,1.
Note 2: 48M_DOT clock is constant at 48MHz and REF is constant at 14.31818MHz for all table selections.
* Will be set to 133MHz and boosted accordingly, when Byte 3 Bit0 is set to logic 1.
Table 2
Power Management Functions
Power Management on this device is controlled by the PD#, CPU_STP# and PCI_STP# pins. When PD# is high
(default) the device is in normal running mode and all signals are active.
The PD# signal is used to bring all clocks to a low level in an orderly fashion prior to power (all except AVDD) being
removed from the part. When PD# is asserted (forced) low, the device transitions to a shutdown (power down) mode
and all power supplies (3.3V and 2.5V except for AVDD) may then be removed. When PD# is sampled low by two
consecutive rising edges of CPU clock, then all affected clocks are stopped in a low state on their next high-to-low
transition. The REF and USB clocks are stopped in a low state as soon as possible. When in power down (and before
power is removed), all outputs are synchronously stopped in a low state (see Figure 1 below), all PLL’s are shut off, and
the crystal oscillator is disabled. When the device is shutdown, the I²C function is also disabled.
At power up, using the PD# select pin, all clocks are started in such a manner as to guarantee a glitch free operation, no
partial clock pulses.
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.,
MILPITAS, CA 95035, USA TEL: 408-263-6300, FAX 408-263-6571
http://www.imicorp.com
Rev 1.0
3/30/2000
Page 3 of 20
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