ICS950813 Datasheet, PDF (5/22 Pages) Integrated Circuit Systems – Frequency Generator with 200MHz Differential CPU Clocks

ICS950813
Advance Information
Host Swing Select Functions
MULTSEL Board Target
Reference R,
0
50 ohms
Rr = 221 1%,
Iref = 5.00mA
1
50 ohms
Rr = 475 1%,
Iref = 2.32mA
Output
Ioh = 4 * I REF
Voh @ Z
1.0V @ 50 ohm
Ioh = 6 * I REF
0.7V @ 50 ohm
PCI Select Functions
E_PCICLK1
E_PCICLK3
0
0
0
1
1
0
1
1
Note:
E_PCICLK1 = 10Kohm resistor.
E_PCICLK3 = 10Kohm resistor.
0 = No resistor
1 = 10Kohm pull-up to V_DD.
* _{Approximate values}
E_PCICLK(3,1)^*
0ns
0.5ns
1.0ns
1.5ns
Frequency Select Table 2
Freqency Select
FS4 FS3 FS2
CPU, 3V66, PCI
0
0
0 Standard Clocking
0
0
1 Standard Clocking
0
1
0 Standard Clocking
0
1
1 Standard Clocking
1
0
0 Pwr Save Clocking
1
0
1 3% Overclocking
1
1
0 5% Overclocking
1
1
1 10% Overclocking
Clocking Mode
0.3% Center Spread
0 to -0.5%, Down Spread
0.3% Center Spread
0 to - 0.75%, Down
Spread Off
0.3% Center Spread
0.3% Center Spread
0.3% Center Spread
PWRSAVE# = '1'. as
PWRSAVE# is driven back to
high '1'. The output frequencies
will be driven back to the
original programmed
frequencies smoothly. Notice
that this operation will only
happen after the PWRSAVE#
has been driven to '0'. This will
not affect power up or I2C
programmed frequencies if the
PWRSAFE# has been tied to a
'1'.
PWRSAVE# Usage Illustration
Bit4 Bit3 Bit2 Bit1 Bit0 CPU AGP PCI
FS4 FS3 FS2 FS1 FS0 MHz MHz MHz
X
X
X
0
0
XXX XXX XXX
X
X
X
0
1
XXX XXX XXX
X
X
X
1
0
XXX XXX XXX
X
X
X
1
1
XXX XXX XXX
1
0
0
0
0 80.00 53.33 26.67
1
0
0
0
1 106.66 53.33 26.67
1
0
0
1
0 160.00 53.33 26.67
1
0
0
1
1 _{133.33 53.33 26.67}
0708—10/10/02
5
PWRSAVE# = '0'. as
PWRSAVE# is driven to low '0'.
The output frequencies of the
CPU, AGP and PCI clock will
smoothly switch to frequencies
indicated by FS (4:2) = 100. The
frequencies gear ratio will be kept
the same. Notice that the 48MHz
& REF frequencies will not be
changed. This function can be
used with asynchronous
AGP/PCI frequencies.