MT9076
Access to the Maintenance Channel
Preliminary Information
The T1 ESF Facility Data Link (FDL) bits can be accessed in the following three ways: Through the data link
pins TxDL, RxDL, RxDLC and TxDLC; through internal registers for Bit Oriented Messages; through an
embedded HDLC.
In E1 mode, the Sa bits (bits 4-8 of the non-frame alignment signal) can be accessed in four ways: Through
data link pins TxDL, RxDL, RxDLC and TxDLC, through single byte transmit and receive registers; through five
byte transmit and receive national bit buffers; through an embedded HDLC.
Robbed Bit Signaling/Channel Associated Signaling
Robbed bit signaling and channel associated signaling information can be accessed two ways: Via the
microport; via the CSTi and CSTo pins. Signaling information is frozen upon loss of multiframe alignment.
In T1 mode, the MT9076 supports AB and ABCD robbed bit signaling. Robbed bit signaling can be enabled on
a channel by channel basis.
In E1 mode the MT9076 supports Channel Associated Signaling (CAS) multiframing.
HDLCs
The MT9076 provides three embedded HDLCs with 128 byte deep transmit and receive FIFOs.
In T1 mode, the embedded HDLCs can be assigned to any channel and can operate at 56 kbit/s or 64 kbit/s. In
T1 ESF mode, HDLCO can be assigned to the 4 kbit/s FDL.
In E1 mode, the embedded HDLCs can be assigned to any timeslot and can operate at 64kbit/s. HDLCO can
be assigned to timeslot 0 Sa bits (bits 4-8 of the non-frame alignment signal) and can operate at 4,8,12,16 or
20kbit/s.
Performance Monitoring and Debugging
The MT9076 has a comprehensive suite of performance monitoring and debugging features. These include
error counters, loopbacks, deliberate error insertion and a 2
15
–1 QRS/PRBS generator/detector.
Interrupts
The MT9076 provides a comprehensive set of maskable interrupts. Interrupt sources consist of
synchronization status, alarm status, counter indication and overflow, timer status, slip indication, maintenance
functions and receive signaling bit changes.
8
MITEL [ MITEL NETWORKS CORPORATION ]
