PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 42

• Manufacturer Part Number: PEB2085
• Description: ISDN SubscribernAccess Controller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Timing Mode 1 (SPM = 1)
Timing mode 1 (SPM = 1) is only meaningful in exchange applications (LT-S, LT-T) when the
SLD is used.
In timing mode 1 the SLD operates in slave mode and the SSI (Serial Port A) is no longer
available.
The IOM is synchronized by a frame signal FSD delayed in time respect to the frame sync
pulse input via FSC1. This reduces the B-channel round-trip delay time when the SLD is used
(figure 15).
For correct operation in timing mode 1, the output FSD should be connected to the FSC2 input
(see figures 11 and 15).
Figure 15
IOM
Semiconductor Group
®
-1 Interface Signals/Timing Mode 1
FSC (Syst.)
SLD (Syst.)
CLK (Syst.)
FSC1 (System)
FSC2 (IOM
R
)
SLD
FSC1
SIP
ISAC -S
1/8 Frame Period
R
FSC2
IDP0
IDP1
DCL
FSD
42
IOM
R
IDP1: = 256 kbit/s
IDP0: = 256 kbit/s
DCL: = 512 kbit/s
FSC: = 8 kHz
IOM
Compatible
Controller
Functional Description
R
LT-T, LT-S Mode
Timing Mode 1
ITS02328