NXP Semiconductors LPC11U1x, User Manual

Page: 468 / 523

UM10462 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2016. All rights reserved.
User manual Rev. 5.5 — 21 December 2016 468 of 523
NXP Semiconductors
UM10462
Chapter 24: LPC11U3x/2x/1x Appendix ARM Cortex-M0
ADD{S} { Rd ,} Rn , <Rm|#imm>
RSBS { Rd ,} Rn , Rm , #0
SBCS { Rd ,} Rn , Rm
SUB{S} { Rd ,} Rn ,
< Rm | #imm >
Where:
S causes an ADD or SUB instruction to update flags
Rd specifies the result register
Rn specifies the first source register
Rm specifies the second source register
imm specifies a constant immediate value.
When the optional Rd register specifier is omitted, it is assumed to take the same value as
Rn , for example ADDS R1,R2 is identical to ADDS R1,R1,R2.
24.4.5.1.2 Operation
The ADCS instruction adds the value in Rn to the value in Rm , adding a further one if the
carry flag is set, places the result in the register specified by Rd and updates the N, Z, C,
and V flags.
The ADD instruction adds the value in Rn to the value in Rm or an immediate value
specified by imm and places the result in the register specified by Rd .
The ADDS instruction performs the same operation as ADD and also updates the N, Z, C
and V flags.
The RSBS instruction subtracts the value in Rn from zero, producing the arithmetic
negative of the value, and places the result in the register specified by Rd and updates the
N, Z, C and V flags.
The SBCS instruction subtracts the value of Rm from the value in Rn , deducts a further
one if the carry flag is set. It places the result in the register specified by Rd and updates
the N, Z, C and V flags.
The SUB instruction subtracts the value in Rm or the immediate specified by imm . It
places the result in the register specified by Rd .
The SUBS instruction performs the same operation as SUB and also updates the N, Z, C
and V flags.
Use ADC and SBC to synthesize multiword arithmetic, see Section 24.4.5.1.4 .
See also Section 24–24.4.4.1 .
24.4.5.1.3 Restrictions
Table 429 lists the legal combinations of register specifiers and immediate values that can
be used with each instruction.