Mitel NWK954 manual Backplane data input enable. Enables the external

NWK954

Expansion Port (Continued)

Signal	Pin no.	Type	Description
BPACTIN_N7	89	Digital input,	Backplane activity inputs. Indicate activity on up to 7
BPACTIN_N6	90	no pull-up	other hubs connected to the backplane. Received from the
BPACTIN_N5	91		backplane via external receivers. Each NWK954
BPACTIN_N4	92		connected to the local expansion bus receives all of these
BPACTIN_N3	101		backplane activity inputs. Unused inputs must be pulled
BPACTIN_N2	102		high or connected directly to DIGVDD. Inputs are sampled
BPACTIN_N1	103		on the rising edge of TXCLKIN.
BPDIE_N	107	Standard digital	Backplane data input enable. Enables the external
		output and digital	receivers that pass backplane data and clock onto the local
		input with pull-up	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 10kΩ pull-down.
BPDOE_N	108	Standard digital	Backplane data output enable. Enables the external
		output and digital	drivers that pass the local IRD[4:0] and BPCLK signals
		input with pull-up	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 10kΩ pull-down.
BPCLK	96	High drive open	25MHz backplane clock. Data transitions on IRD[4:0] are
		drain digital output	synchronised to this clock. When another hub in the stack
		and digital input	is sourcing data, this clock is received from the backplane
		with pull-up	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
BPCOL_N	95	High drive open	Backplane collision. This signal may be driven by any of
		drain digital output	the local NWK954s to indicate that a collision has been
		and digital input	detected, and is supplied to the backplane through an
		with pull-up	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.
BPCOLIN_N	104	Digital input,	Backplane collision input. Indicates that a collision has
		no pull-up	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.
BPCOLOE_N	106	Standard digital	Backplane collision output enable. Enables the external
		output and digital	driver that passes BPCOL_N onto the backplane. Only one
		input with pull-up	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 10kΩ
			pull-down.
			.
		Table 5 (continued)

10