The doc should have read. SUB works the same as for other LDR/STR index functions. The 'S' bit is always zero.
Syntax: TESTSET RD, [RN, +/-RM];
Flags Updated: None
Operation: if ([RN+/-RM]) {
RD= ([RN+/-RM])
}
else{
([RN+/-RM])=RD
RD=0;
}
Manual and opcode table has been updated, will be included in next publishing.
Thanks!
Andreas