RM48L952: Hercules RM48L952 DMIPS rating

Support Path: /Product/Help with Device Selection/

Hello,

I have a RM48L952 HDK board.  Our product will be battery powered so we will run with a 40 MHz clock rate to save power.  I configured HALCoGen for a HCLK = GCLK = PLL1 = 40 MHz.  The CPU Clock and peripherals are also set to 40 Mhz.  I built the code and added a FOR loop that counts to 100,000 then toggles an LED.  The LED toggles every 40 mS.  I have interrupts disabled for this test. I looked at the assembly code produced for this loop (shown below).  There are a total of 9 opcodes executed while counting from 0 to 100,000.

My question:  9 opcodes x 100,000 in 40 mS results in about 22,500,000 instructions per second.  But the RM48L9xx is advertised to run at 1.66 DMIPS/MHz.  So I would expect about 66,000,000 instructions per second (1.66 x 40 MHz) and my loop should execute almost 3 times faster.

Is there some RM48L952 clock output on the HDK board that I can look at to see if the IC is actually running at 40 MHz?  The code is running from internal FLASH, so the external memory bus is not active.  What else can I look at to verify that I am actually running at 40 MHz?

Thank you,

Keith

============ for (i=0; i< 100000; i++)

$C$L61:
000189dc:   E59F0144            ldr        r0, [pc, #0x144]
000189e0:   E590C000            ldr        r12, [r0]
000189e4:   E28CC001            add        r12, r12, #1
000189e8:   E580C000            str        r12, [r0]
 67                if (idleCount > 100000) {
000189ec:   E59FC134            ldr        r12, [pc, #0x134]
000189f0:   E59F0134            ldr        r0, [pc, #0x134]
000189f4:   E59CC000            ldr        r12, [r12]
000189f8:   E150000C            cmp        r0, r12
000189fc:   2AFFFFF6            bhs        $C$L61