I need to do a multiplication in the keil and the following mistake goes out for me. It does not leave me to use MLU and MUL. Why?
error: A1477W: This register combination results in UNPREDICTABLE behaviour
Neither MLA nor MUL allow the use of the first operand register as destination. This limitation also exists for ARM Code. Only a wide Thumb2 would allow this.
Regards Marcus http://www.doulos.com/arm/
agree.
your fault is to write asm code in the c style.
I guess "MLA R9,R3,R4,R2" will work.
That restriction is not mentioned in http://www.keil.com/support/man/docs/armasm/armasm_cihihggj.htm
In fact,
MLA R3,R4,R3,R2
will do.