Mitel NWK954 - Manual (Page 10)

NWK954
10
Expansion Port (Continued)
Signal
BPACTIN_N7
BPACTIN_N6
BPACTIN_N5
BPACTIN_N4
BPACTIN_N3
BPACTIN_N2
BPACTIN_N1
BPDIE_N
BPDOE_N
BPCLK
BPCOL_N
BPCOLIN_N
BPCOLOE_N
Type
Digital input,
no pull-up
Standard digital
output and digital
input with pull-up
Standard digital
output and digital
input with pull-up
High drive open
drain digital output
and digital input
with pull-up
High drive open
drain digital output
and digital input
with pull-up
Digital input,
no pull-up
Standard digital
output and digital
input with pull-up
Pin no.
89
90
91
92
101
102
103
107
108
96
95
104
106
Description
Backplane activity inputs. Indicate activity on up to 7
other hubs connected to the backplane. Received from the
backplane via external receivers. Each NWK954
connected to the local expansion bus receives all of these
backplane activity inputs. Unused inputs must be pulled
high or connected directly to DIGVDD. Inputs are sampled
on the rising edge of TXCLKIN.
Backplane data input enable. Enables the external
receivers that pass backplane data and clock onto the local
IRD[4:0] and BPCLK lines. Only one of the local NWK954s
is required to drive this signal, the others should be left
unconnected. This signal changes asynchronously.
Polarity defaults to active low but may be switched to
active high by adding an external 10k
Ω
pull-down.
Backplane data output enable. Enables the external
drivers that pass the local IRD[4:0] and BPCLK signals
onto the backplane. Output changes on the rising edge of
TXCLKIN. Only one of the local NWK954s is required to drive
this signal, the others should be left unconnected. Polarity
defaults to active low but may be switched to active high by
adding an external 10k
Ω
pull-down.
25MHz backplane clock. Data transitions on IRD[4:0] are
synchronised to this clock. When another hub in the stack
is sourcing data, this clock is received from the backplane
to all local NWK954s through an external receiver. When a
local NWK954 is sourcing data, BPCLK is supplied to the
backplane through an external driver. Requires external
pull-up for correct operation
Backplane collision. This signal may be driven by any of
the local NWK954s to indicate that a collision has been
detected, and is supplied to the backplane through an
external driver. Output transitions are synchronous to
the rising edge of TXCLKIN and the input is sampled on the
rising edge of TXCLKIN. Requires external pull-up for correct
operation.
Backplane collision input. Indicates that a collision has
been detected by any hub in the stack. Received from the
backplane via an external receiver. Connects to all local
NWK954s. Must be pulled high or connected directly to
DIGVDD if not used. Input is sampled on the falling edge of
TXCLKIN.
Backplane collision output enable. Enables the external
driver that passes BPCOL_N onto the backplane. Only one
of the local NWK954s is required to drive this signal, the
others should be left unconnected. Output changes on the
rising edge of TXCLKIN. Polarity defaults to active low but
may be switched to active high by adding an external 10k
Ω
pull-down.
.
Table 5 (continued)