SWAN 2 Concentrator Installation and Support Guide

Cable Specifications
SWAN 2 Concentrator Installation and Support Guide—429593-010
C-21
Interface Select (ISEL) Code
The four-bit ISEL value is %b0000.
Interface Select (ISEL) Code
The ISEL code us a 4-bit code read by each CLIP on a SWAN 2 concentrator to
determine which type of cable or loopback test connector is installed in a WAN port.
Each connector has a unique ISEL code.
Three bits (ISEL3, ISEL2, and ISEL1) are needed to code six connector configurations;
the fourth bit, ISEL0, is an even parity bit used to confirm that the connector is properly
seated. The seating is done by using four corner pins on the connector: the right top,
right bottom, left top, and left bottom pins as you face the connector. There is at least
one zero bit on each of the right and left sides for all connectors.
Because many pins of the loopback test connector are shared by the different
interfaces, the loopback test connector requires more information than just the 4-bit
ISEL code. The Power QUICC2 writes TX_LOOP_SEL bits, which select which drivers
to enable when the loopback connector is connected.
Table C-12. ISEL Codes
Interface
ISEL3
(Right
Top)
17
ISEL2
(Right
Bottom)
50
ISEL1
(Left
Top)
1
ISEL0
(Left
Bottom)
34
TX_LOOP_
SEL ISEL_CODE
RS-2321001XX 100
RS-4491010XX 101
X.210101XX 010
V.350110XX 011
Loopback
(RS-232)
000000
Loopback
(RS-449)
000001
Loopback
(X.21)
000010
Loopback
(V.35)
000011
No
connector
1111xx 111