+/+…when timing is critical
C9809B
Low EMI Clock Generator for Intel 133MHz/3DIMM Chipset Systems
Preliminary
Power on Bi-Functional Pins (Cont.)
Pin 30 (TS# / PD#) is a bi-functional pin, See Fig.6. If this pin is externally held low during power up, the device is forced
into tristate/or test mode depending on the state of Sel0.
In Tristate mode, all outputs assume the high impedance (Hi-Z) state. In test, all outputs toggle as described in table 2,
page 3.
All outputs remain in their Hi-Z state (or test mode) until the external signal applied to pin 30 is released (set high). After
a minimum of 1.5mS from a stable 3.3V power supply or until TS# is released (whichever is longer), pin 30 changes
from a tristate controller (TS#) to Power Down controller (PD#) and remains in that function unless otherwise
programmed through the I2C to return to the TS# function by setting byte3, bit1 to a “0”. Once the TS# signal is released
(high), pin 30 may be toggled repetitively to force the device in and out of power down mode.
The device is considered in power down when PD# is asserted low, consequently, all clocks are stopped synchronously
and after the completion of a full period (glitch-free).
3.3V
Power
Supply
TS# function
TS# asserted
low
TS# released
PD# asserted low
PD# released
TS#
ς
TS# function
Default High
PD#
ς
I2C,
Byte3,
Bit1
programmed Low
Toggle
Hi-Z
Hi-Z
Output
Clock
Power Down
ς
ς
Fig.6
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.,
Rev 1.2
3/8/2000
MILPITAS, CA 95035, USA. TEL: 408-263-6300, FAX 408-263-6571
http://www.imicorp.com
Page 7 of 20
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