3.7.1. The N, Z, C, and V bits

The N, Z, C, and V bits are the condition code flags. You can optionally set them with arithmetic and logical operations, and also with MSR instructions and MRC instructions to R15. The processor tests these flags in accordance with an instruction's condition code to determine whether to execute that instruction.

In ARM state, most instructions can execute conditionally on the state of the N, Z, C, and V bits. The exceptions are:

In Thumb state, the processor can only execute the Branch instruction conditionally. Other instructions can be made conditional by placing them in the If-Then (IT) block. For more information about conditional execution in Thumb state, see the ARM Architecture Reference Manual.

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