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

Assembler syntax
VLDM{}{.} {!},
where:
The addressing mode:
Instruction Details
IA Increment After. The consecutive addresses start at the address specified in .
This is the default and can be omitted. Encoded as P = 0, U = 1.
DB Decrement Before. The consecutive addresses end just before the address
specified in . Encoded as P = 1, U = 0.
See Standard assembler syntax fields on page A8-7.
An optional data size specifier. If present, it must be equal to the size in bits, 32 or 64, of the
registers in .
The base register. The SP can be used. In the ARM instruction set, if ! is not specified the
PC can be used.
! Causes the instruction to write a modified value back to . This is required if
== DB, and is optional if == IA. Encoded as W = 1.
If ! is omitted, the instruction does not change in this way. Encoded as W = 0.
The extension registers to be loaded, as a list of consecutively numbered doubleword
(encoding T1 / A1) or singleword (encoding T2 / A2) registers, separated by commas and
surrounded by brackets. It is encoded in the instruction by setting D and Vd to specify the
first register in the list, and imm8 to twice the number of registers in the list (encoding
T1 / A1) or the number of registers in the list (encoding T2 / A2). must contain at
least one register. If it contains doubleword registers it must not contain more than 16
registers.
Operation
if ConditionPassed() then
EncodingSpecificOperations(); CheckVFPEnabled(TRUE); NullCheckIfThumbEE(n);
address = if add then R[n] else R[n]-imm32;
if wback then R[n] = if add then R[n}+imm32 else R[n]-imm32;
for r = 0 to regs-1
if single_regs then
S[d+r] = MemA[address,4]; address = address+4;
else
word1 = MemA[address,4]; word2 = MemA[address+4,4]; address = address+8;
// Combine the word-aligned words in the correct order for current endianness.
D[d+r] = if BigEndian() then word1:word2 else word2:word1;
Exceptions
Undefined Instruction, Data Abort.
ARM DDI 0406B Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. A8-627