ARM VERSION 1.2 - Manual (Page 160)

ARM Instruction Reference
4-50 Copyright © 2000, 2001 ARM Limited. All rights reserved. ARM DUI 0068B
Architectures
This instruction is available in all E variants of ARM architecture v5 and above.
Examples
SMLAWB r2,r4,r7,r1
SMLAWTVS r0,r0,r9,r2
Incorrect examples
SMLAWT r15,r9,r3,r1 ; use of r15 not allowed
SMLAWBS r0,r4,r5,r1 ; use of S suffix not allowed