WAYNE, N.J. Vocal Technologies has developed a reference design that the company claims will allow designers to develop a voice-over-IP (VoIP) analog terminal adapter (ATA) for under $20.
Unlike many developers, which are looking to collapse VoIP processing on a RISC process, Vocal (Buffalo, N.Y.) opted to take the control tasks and port them to the digital signal processor (DSP), thus eliminating the need for a RISC engine. "There is a problem with porting all processing to a RISC," said Vocal CTO Victor Demjanenko, "The RISC requires 3X more cycles to run an algorithm when compared to a DSP." This increased cycle count, he added, will force designers looking at a RISC-only approach to implement a larger, more-costly RISC device.
Concerned about the cost of the RISC approach, Vocal looked in the other direction, opting to bring the RISC functions to the DSP. "We took the approach that is you used software that was less complex than traditional VoIP ATAs, you could run all functions on a well-provisioned DSP," Demjanenko said.
The simpler software approach, along with the use of an in-house operating system, allowed Vocal to create a structure where both control/networking tasks and voice processing tasks can be handled on a Texas Instruments TMS320C5502 DSP. Specifically, Demjanenko said the architecture splits the processing tasks executing real-time tasks in the foreground and control/networking tasks in the background.
The reference design is available in several configurations. Two of the more popular will be a 1x1 configuration (one analog port and one Ethernet port) and a 2x1 configuration (two analog ports and 1 Ethernet port). The company is also offering a 1x0 design (one analog port) with a USB interface that allows designers to attach to a PC. In the 1x0 reference design, the PC's host CPU handles all processing tasks in software.
The reference designs are available now. In volume, the 1x1 platform will be priced at less than $20 and the 1x0 design will be available for approximately $6.