ACD82224 Datasheet, PDF (27/77 Pages) List of Unclassifed Manufacturers – 24 Ports 10/100 Fast Ethernet Switch

Other Interface
Table-6.12: Other Signals
Name
CLK100
NRESET
WCHDOG
SYSERROR
ZBTCLK
CLKSEL, EN16P, TESTEN
VDD
VDDC
VSS
Type
I
I
O
O
O
I
I
I
I
Description
100 MHz clock input
Hardware reset, low active
Watch dog life pulse
system error indication
Factory use only
Factory use only
3.3V power
2.5V power
Ground
The CLK100 should come from 100MHz clock oscillator, with 3.3Volt or 5Volt, 40/60 Duty Cycle,
and 50 ppm accuracy.
The nRESET is a low-active hardware reset pin. Assertion of this pin will cause the ACD82224 to
go through a power-up initialization process. All registers are set to their default value after reset.
The WCHDOG pin is used to handle exceptional cases. A normal working ACD82224 sends out
continuous life pulses from the WCHDOG pin, which can be monitored by an external watchdog
circuit. If no life pulse is detected, the external watchdog circuit may force reset of the switch
system. It is a safeguard against unforeseeable situations.
The SYSERROR is System error indication and it’s high active. When there is any error occurs in
SYSERR Register it’s asserted to HIGH until the SYSERR Register been read.
The CLKSEL, EN16P, and TESTEN are input pins for factory test use only. These three pins must be
connected to ground directly. The ZBTCLK is output pin and also for factory use. Do not connect the
ZBTCLK.
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