SP508EB Datasheet, PDF (8/10 Pages) Sipex Corporation – Evaluation Board Manual

DIP SWITCH USERS GUIDE
Driver Enable Dip Switch
(off = logic 1, on = logic 0)
The individual switches in the off position
leaves the individual enable pin floating (in-
ternally pulled up or down?) which enables
the driver. The switch in the on position ties
the high true enable pins to ground and the
low true enable pin (LLEN) to V_CC thereby
disabling the individual drivers.
Receiver Enable Dip Switch
(off = logic 0, on = logic 1)
The individual switches in the off position
leaves the individual enable pins floating
(internally pulled down or up?) which en-
ables the receiver. The switch in the on
position ties all of the enable pins to V_CC
even the high true TMEN. The TMEN pin is
always high no matter what position the dip
switch is in. To disable the TM receiver the
DIP switch must be off and the external pin
labeled TMEN is to be jumped to ground.
Decoder DIP Switch
(off = logic 1, on = logic 0)
The decoder DIP switch is configured such
that the switch in the off position allows the
decoder pins to float as well as the
notLOOPBACK pin. (all of these pins are
assumed to have internal pull-ups.) The dip
switch in the on position grounds each of
these pins.
DCE_DTE Selectable Switches
• Switch bank 1 ON = ST driver outputs tied
to TxC receiver inputs and also tied to D-
SUB connector for remote evaluation.
• Switch bank 2 ON = RRC driver outputs
tied to RRT receiver inputs and also tied to
D-SUB connector for remote evaluation.
SP508 DIP SWITCH TRUTH TABLE
Switch
D0
D1
D2
LOOPBACK
TERM_OFF
D_LATCH
SDEN
TTEN
STEN
RSEN
TREN
RRCEN
RLEN
LLEN
RDEN
RTEN
TXCEN
CSEN
DMEN
RRTEN
ICEN
TMEN
ON LOGIC
0
0
0
0
1
1
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
OFF LOGIC
1
1
1
1
0
0
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
DECODER
DECODER
DECODER
Logic 0 indicates SP508 is in LOOPBACK mode
Logic 1 internal termination is disables
Logic 0 Latch is disabled
Logic 1 TXD driver is enabled
Logic 1 TXCE driver is enabled
Logic 1 ST driver is enabled
Logic 1 RTS driver is enabled
Logic 1 DTR driver is enabled
Logic 1 DCD_DCE driver is enabled
Logic 1 SD driver is enabled
Logic 0 LL driver is enabled
Logic 0 RXD receiver is enabled
Logic 0 RXT receiver is enabled
Logic 0 TXC receiver is enabled
Logic 0 CTS receiver is enabled
Logic 0 DSR receiver is enabled
Logic 0 DCD_DTE receiver is enabled
Logic 0 RI receiver is enabled
Logic 1 TM receiver is enabled
rev. 7/7/03
SP508 Evaluation Board Manual
8
© Copyright 2003 Sipex Corporation