P
R
E
L
I
M
I
N
A
R
Y
I
N
F
O
R
M
A
T
I
O
N
XpressFlow-2020 Series –
Ethernet Switch Chipset
SC220
XpressFlow Engine
S_CLK
S_MSGEN#
S_REQ[j]#
S_GNT[j]#
S_HPREQ#
S_REQ[I]#
S_GNT[I]#
XpressFlow Bus arbitration
S_CLK
S_REQ[k]#
S_OVLD#
Bus Overload pre-empts the data transfer request
2.5 Test Pins
Symbol
TEST
Type Name & Functions
CMOS Test Mode Selection & Test Output – Set Test Mode upon Reset,
I/O
and provides test status output during test mode
© 1998 Vertex Networks, Inc.
22
Rev. 4.5 – February
1999