IDT821068

The IDT821068 is a feature rich, single-chip, programmable 8 channel PCM CODEC with on-chip filters. Besides the A-Law/m-Law companding and linear coding/decoding (16-bit 2's complement), IDT821068 provides 2 programmable Tone generators per channel (which can also generate ring signals), 1 FSK generator, 1 programmable Teletax Signal generator and 2 programmable chopper clocks for SLIC.

The digital filters in IDT821068 provide the necessary transmit and receive filtering for voice telephone circuit to interface with time-division multiplexed systems. An integrated programmable DSP realizes AC Impedance Matching, Transhybrid Balance, Frequency Response Correction and Gain Setting functions. The IDT821068 supports 2
PCM buses with programmable sampling edge, that allows an extra delay of up to 7 clocks. Once the delay is determined, it is effective to all eight channels of IDT821068. The device also provides 7 signaling pins to SLIC on per channel basis.

The IDT821068 provides 2 programming interfaces: Microprocessor Interface (MPI) and General Control Interface (GCI), which is also known as ISDN Oriented Module (IOM®-2). For both MPI and GCI programming, the device supports both compressed and linear data format.

IDT821068 also offers strong test capability with several analog/ digital loopbacks and level metering function. It brings convenience to system maintenance and diagnosis.

A unique feature of 'Hardware Ring Trip' is implemented in IDT821068. When off-hook signal is detected, it can reverse an output pin to stop ringing immediately.

The IDT821068 can be used in digital telecommunication applications such as Central Office Switch, PBX, DLC and Integrated Access Device (IAD), i.e. VoIP and VoDSL.