ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Instruction Details
A8.6.393 VST2 (multiple 2-element structures)
This instruction stores multiple 2-element structures from two or four registers to memory, with
interleaving. For more information, see Element and structure load/store instructions on page A4-27. Every
element of each register is saved. For details of the addressing mode see Advanced SIMD addressing mode
on page A7-30.
Encoding T1 / A1 Advanced SIMD
VST2. , [{@}]{!}
VST2. , [{@}],
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 1 1 1 0 0 1 0 D 0 0 Rn Vd type size align Rm
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 1 1 0 1 0 0 0 D 0 0 Rn Vd type size align Rm
if size == ‘11’ then UNDEFINED;
case type of
when ‘1000’
regs = 1; inc = 1; if align == ‘11’ then UNDEFINED;
when ‘1001’
regs = 1; inc = 2; if align == ‘11’ then UNDEFINED;
when ‘0011’
regs = 2; inc = 2;
otherwise
SEE “Related encodings”;
alignment = if align == ‘00’ then 1 else 4