MIPS

Kannan,

MIPS is a term that really depends on how you define it.  Technically, it stands for Millions of Instructions per Second.  But that is not necessarily a useful spec.  It depends on what those instructions do.  A RISC machine for example can execute multiple instructions in parallel, but you're probably not doing multiple different things.  Just to do an add of two numbers would require two loads and an ADD.  Compare to a CISC machine that has a single ADD instruction that has the two loads built in.  Based on MIPS, you'd think the RISC machine is 3x more powerful (3 instructions per cycle) than the CISC machine.  This would be a bad conclusion.

Some people use MAC (multiply and accumulates) to gauge the performance of DSP like devices.  Even that can depend on how you define MAC.  Do you mean 16-bit MACs, 32-bit MACs, single-precision floating-pt. MACs?

All the above said, C28x devices are basically one instruction per clock cycle for the CPU itself.  However, some of the devices you cited also have the CLA (control law accelerator) which is an independent mini-CPU, and the F28377D has two CPUs and two CLAs.  So:

         MHz  #CPU  #CLA  MIPS
F28069F   90    1     1   180
F28068F   90    1     1   180
F28062F   90    1     1   180
F28335   150    1     0   150
F28377D  200    2     2   800

The above MIPS are total MIPS for all CPUs and CLAs combined.  In single threaded applications, you may not be able to utilize the CLA.  Depends on the application.  In some applications such as motor control, the CLA is readily adaptable to do the control loop while the main CPU can handle communications, trajectory planning, housekeeping, etc.

Regards,

David

Kannan,

I assume by DMIPs you mean Dryhstone MIPS.  The C28x achieves roughly 1 DMIPS/MHz.  But, be very careful using the DMIP benchmark.  DMIP is a measurement of the general purpose capability of a processor.  It is dominated by string copies and compare operations.  It is a very poor indicator of the math computation capability of a processor.  For example, ARM Cortex-M CPU achieves 1.25 DMIPS/MHz.  But for math capability, the C28x is significantly better.

Regards,

David