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=== Background on Setup (Arm) ===
For the rest of this tutorial, we'll be focusing on the STM32F3, which is the microcontroller on the CW303 Arm target (though other targets should demonstrate the same principles). Since the STM32F3 is an Arm Cortex M4 device, we'll need to refer to the [http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0553a/CHDJJGFB.html Cortex M4 Instruction Set ] and the [http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0439b/CHDDIGAC.html Cortex M4 Instruction Set Summary].
The first thing we'll do is replace the <code>nop</code> instructions, since from it's documentation page we can see the processor may not execute them. Instead, let's add some <code>add.w</code> (which is the 32 bit wide version of the add instruction) instructions. We'll be doing this since the <code>mul</code> instruction is always 32 bits wide and the 16 bit thumb instruction has a different power profile than the 32 bit Arm instruction. From the earlier links, we can see that both add and mul take 1 cycle each to complete.
