MTC-20172-PC AMI Semiconductor, Inc., MTC-20172-PC Datasheet - Page 64

• Manufacturer Part Number: MTC-20172-PC
• Description: S Interface Circuit for ISDN (SIC)
• Manufacturer: AMI Semiconductor, Inc.

6.5.6 Extended Mode Commands and Indications
The MTC-20172 SIC implements the full list of C/I codes of the extended mode
as indicated below:
Table 6.2: Extended mode commands and indications
[]+: The commands "scz" (=TM2) and
"ei" were added to remove
differences between modes.
This list follows the stable GCI version
of the names, abbreviations and
positions of the C/I codes.
The detailed explanation of each
command is given below in the 6.5.8
to 6.5.10.
mode
C/I
code
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1001
1100
1101
1110
1111
Downstr
Indicat.
DR
RES
TM
SLIP
RSY
PU
AR
-
ARL
-
-
-
AI8
AI10
AIL
DC
Terminal equipm.
TE/LT-T
Upstr.
Command
TIM
RES
TM1
TM2
[scz]+
-
-
-
AR8
AR10
ARL
-
-
-
-
DI
The NT-STAR C/I channel issue:
The MTC-20172 sic does not support
the functional combination of the c/I
codes in the nt-star configuration.
If two SICs in an NT are put in STAR
configuration, see 5.6.1, the C/I
channels will coincide on the GCI bus.
The DOUT pin is configured as open
drain (see TABLE 3.3), thus no electrical
problems exist. However, the indications
of both SICs will be wired-ANDed on
the bus, bit by bit, and the result is
incorrect. E.g., when one branch of the
STAR has no TE, then it is not
Downstr
Command
DR
RES
TM1
TM2
RSY
-
-
-
AR
-
ARL
-
AI
-
AIL
DC
network termin.
54
NT
Upstr.
Indicat.
TIM
-
-
-
RSY
-
[ei]+
-
AR
-
-
-
AI
-
-
DI
synchronous and it signals "RSY", while
the other branches try to indicate "AI".
The combination is still "0100", which is
"RSY".
NOTE: Some devices use the CEB pin,
which links all devices in the NT-STAR,
to allow the AI uplink indications in the
C/I channel, when at least one device
reaches the G3 Activated state (5). The
MTC-20172 SIC does not support this.
MTC-20172
Data Sheet & Reference Manual
Rev. 1.1 February 1997
Downstr
Command
DR
RES
TM1
TM2
-
-
-
-
AR
-
ARL
-
-
-
-
DC
line termination
LT-S
Upstr.
Indicat.
TIM
-
-
-
RSY
-
-
-
AR
-
-
-
AI
-
-
DI