Slide 16 of 16
Notes:
In this “enterprise server” the customer wanted to separate the modem functions from the other DSP functions (echo cancellation and DTMF). One of the reasons for this was for scaling purposes and also since they wanted to use the modem boards (without DTMF and echo cancellation) in other end-equipment applications. DTMF and echo cancellation require about 6 MIPS on a C54x. This would necessitate the use of two 100 MIPS C54x devices to handle the 30 channels -- each DSP would take 15 channels. The processor cost for the two C54x’s would be $66 and the $ per channel would be $2.20. The mW per channel is under 8 mW and the space per channel is around 10 mm2. This application (echo cancellation and DTMF) utilizes only about one-third of the performance offered by one C6201. Therefore, the cost per channel, power per channel, and space per channel are all higher for the C6x in this case. As a result, this application would be best suited for the C54x. However, the customer would need to commit to the code development on two processors. If this is not acceptable, it may make more sense to try and integrate the functionality of the echo cancellation and DTMF onto the modem board (depends upon how adamant the customer is to keeping these apps separate).
