Tone Detector (TN748)
The Tone Detector Circuit Pack provides four
The Tone Detector CP consists of the same common circuitry as the intelligent port circuits and the following unique circuits (see Figure
●Port I/O circuit
●Port or DSP Sanity check circuit
● Four
●Two general purpose tone detector ports
●Two NPE
Up to a maximum of two Tone Detector CPs can be provided in the system.
Port I/O and Sanity Check Circuit: This circuit interfaces the
Port Circuits: There are eight port circuits. Six port circuits are connected to Network Processing Elements (NPEs). Port circuits 0,1, 4, and 5 are DTMF tone detector ports. Each of the six port circuits has an associated Digital Signal Processor (DSP), NPE to DSP interface circuitry, a DSP restart circuit and an interrupt filter. Port circuits 2 and 6 are general purpose tone detector ports. Port circuits 3 and 7 provide digital
The NPE serializes TDM bus signals that are connected to the DSP in serial form from the NPEs by the DSP interface circuit. Serial clock and data signals connect directly from the NPE to the DSP. The system framing signal is synchronized and connects to the DSP.
The DSP restart circuit controls the DSPs. When the
T h e t o u c h - t o n e D S P s , u n d e r c o n t r o l o f t h e o n - b o a r d m i c r o p r o c e s s o r , w r i t e d a t a synchronously to the NPEs. The interrupt filter detects valid