Terry says:
...the non-turbo mode does NOT divide the clock speed. At the slower clock rates it really doesn't save much current at all.Here is the test program:
DEVICE SX28,STACKX,OPTIONX,OSC128KHZ FREQ 128_000 PROGRAM Start NOSTARTUP Start: TRIS_A=0 TRIS_B=0 TRIS_C=0 Main: TOGGLE RB.5 PAUSE 5000 GOTO StartHere is what I measured {ed: this was at 5V supply, consumption would have been much less at 3.3 or 2.5 volts. See: SX Power Issues}
32KHz Turbo = 1.32mA 32KHz Non-Turbo = 1.30mA 128KHz Turbo = 1.46mA 128KHz Non-Turbo = 1.40mA 1MHz Turbo = 3.1mA 1MHz Non-Turbo = 2.4mA 4MHz Turbo = 7.7mA 4MHz Non-Turbo = 5.2mAConsidering that 1MHz Turbo (3.1mA) has the same performance as 4MHz Non-Turbo (5.2mA). It is better to use the turbo mode if you are looking at MIP per mA.
Perl62 says:
Non-turbo mode simply adds a few cycles delay to emualte the instruction timing of a PIC. It's purpose was simply to allow PIC firmware to be directly loaded to the SX and still be able to run.