Datasheet

DS26502
19 of 125
NAME TYPE FUNCTION
A4/CPHA/
L2
I
Address Bus Bit A[4]/Serial Port Clock Phase Select/Line Build-Out
Select 2
A4: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[4].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
CPHA: In Serial Port Mode (BIS[1:0] = 10), this pin selects the serial port
clock phase. See the functional timing diagrams for the Serial Port Interface
for more information.
L2: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out
value.
A3/L1 I
Address Bus Bit A[3]/Line Build-Out Select 1
A3: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[3].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
L1: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out
value.
A2/L0 I
Address Bus Bit A[2]/Line Build-Out Select 0
A2: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[2].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
L0: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out
value.
A1/TAIS
I
Address Bus Bit A[1]/Transmit AIS
A1: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[1].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
TAIS: When set to a 0 and in T1/E1 operating modes, the transmitter will
transmit an AIS pattern. Set to a 1 for normal operation. This pin is ignored in
all other operating modes.
A0/E1TS I
Address Bus Bit A[0]/E1 Termination Select
A0: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[0].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
E1TS: In Hardware Mode (BIS[1:0] = 11), selects the E1 internal termination
value (0 = 75Ω, 1 = 120Ω).
BTS/HBE I
Bus Type Select/Transmit and Receive B8ZS/HDB3 Enable
BTS: Strap high to select Motorola bus timing; strap low to select Intel bus
timing. This pin controls the function of the RD (DS), ALE (AS), and WR
(R/W) pins. If BTS = 1, then these pins assume the function listed in
parentheses ().
HBE: In Hardware Mode (BIS[1:0] = 11), this pin enables transmit and
receive B8ZS/HDB3 when in T1/E1 operating modes.