Slide 13 of 16
Notes:
Taking a look at this application, we are looking at implementing 30 channels of an application like G.723 + V.29 fax or G.728. For this application, we have approximated a 30 MIPS requirement at any one time. While there are multiple algorithms that are needed for this system, G.723 requires about 16.6 MIPS on a C54x and low-level fax or modem code will not be above 14 MIPS. As a result, a total of about 30 MIPS is anticipated which means that ten 100 MIPS C54x’s are required to handle 30 channels. This translates to $330 cost and $11.00 / channel. The power dissipation would be around 40 mw / channel (computed on prior case study) and the space requirement is 65 mm2. For the space requirements, we used 14mm x 14mm which equals 196 mm2. (10 x 196 mm2) / 30 channels = 65.3 mm2. First, why 14mm x 14mm, when the package is only 12mm x 12mm? To be more realistic, we have accounted for some of the routing of the DSPs beyond the package itself. For the C6x, the number of channels that can be handled by the C6x is about 12 per DSP, once again lower than the theoretical performance number of 15 due to memory requirements. This means that 3 C6201’s are not being fully utilized (3 x 12 = 36). In this case, the $ / channel is slightly in favor for C6x and power / channel is in favor of C54x. Either solution is superior to the existing design; it is a tradeoff of careabouts.
