PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 282

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

Low Level Controller
ResL1_SBC ()
This routine resets the layer 1 part of an ISAC-S. It also checks that the layer 1 part is operating
correctly.
Reset procedure:
A software reset command (RS) is sent to the layer 1 part via the IOM CI0 channel.
ResL1_SBC waits for the expected new state (EI) if no timeout condition occurs and issues a
release command (DIU).
If the new state (EI) is not observed the ISAC-S layer 1 part will be deemed to be defective.
IntL1_SBC ()
Interrupt Handler
Handles the CISQ interrupts which indicate changes in the layer 1 status. The final
confirmation of deactivation is carried out here. The actual layer 1 state is evaluated by reading
register CIR0. The following is then carried out:
If the CI channel indication is ’pending deactivation’ state (DR), DIU is sent to deactivate the
layer 1.
If the indication is an ’activation indication’ (AI) the activation must be confirmed from the TE
side. IntL1_SBC does it automatically by writing an ’activation request’ (AR). In this way this
requirement of the ISAC-S is transparent to the higher protocol layers.
After every CI channel status change interrupt (CISQ) DECODE_L1_STATUS is called to
report the current layer-1 state.
®
6.5.2
ISAC
-S HDLC Controller Related Functions: The ICC Part
InitPeitab_ICC ()
Initializes the local variable ’pt’. InitPeitab_ICC is to be called once during the system
initialization phase.
InitLay2_ICC ()
Initializes the HDLC controller. The function arguments allow the selection of the HDLC
controller message transfer mode (auto-mode, non-auto-mode, ...), one or two byte HDCL
control field operation (modulo 8 or 128) and the setting of the ISAC-S internal hardware timer.
After InitLay2_ICC is called the TEI values for a Broadcast Link are programmed (TEI = FF
hex). The HDLC controller is not reset.
StoreTEI_ICC ()
StoreTEI_ICC is used to program a TEI value in register TEI1 or TEI2 depending on the
function argument value.
Semiconductor Group
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