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

A9.5.3 HBLP
ThumbEE
HBLP (Handler Branch with Link and Parameter) saves a return address to the LR, and then branches to a
specified handler. It passes a 5-bit parameter to the handler in R8.
Encoding E1 ThumbEE
HBLP #, #
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 0 0 0 1 imm5 handler
imm32 = ZeroExtend(imm5, 32); handler_offset = ZeroExtend(handler:’00000’, 32);
Assembler syntax
HBLP #, #
where:
See Standard assembler syntax fields on page A8-7.
The parameter to pass to the handler, in the range 0-31.
The index number of the handler to be called, in the range 0-31.
Operation
if ConditionPassed() then
EncodingSpecificOperations();
R[8] = imm32;
next_instr_addr = PC - 2;
LR = next_instr_addr : ‘1’;
BranchWritePC(TEEHBR + handler_offset);
Exceptions
None.
ARM DDI 0406B Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. A9-17