5.2.5. ADC, SBC, and MUL

Add with carry, Subtract with carry, and Multiply.

Syntax

op Rd, Rm

where:

op

is one of ADC, SBC, or MUL.

Rd

is the destination register. It also contains the first operand.

Rm

is a register containing the second operand.

Usage

ADC adds the values in Rd and Rm, together with the carry flag, and places the result in Rd. Use this to synthesize multiword addition.

SBC subtracts the value in Rm from the value in Rd, taking account of the carry flag, and places the result in Rd. Use this to synthesize multiword subtraction.

MUL multiplies the values in Rd and Rm, and places the result in Rd.

Restrictions

Rd, and Rm, must be low registers (that is, in the range r0 to r7).

Condition flags

ADC and SBC update the N, Z, C, and V flags.

MUL updates the N and Z flags.

In ARM architecture version 4 and earlier, MUL corrupts the C and V flags. In ARM architecture version 5 and later, MUL has no effect on the C and V flags.

Architectures

These instructions are available in all T variants of the ARM architecture.

Example

    ADC r2,r4
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