Sp (Push) - Analog Devices ADSP-BF53x Blackfin Reference

Instruction Overview

--SP (Push)

General Form
[ -- SP ] = src_reg
Syntax
[ -- SP ] = allreg ;
Syntax Terminology
: ,
allreg R7–0 P5–0
, ,
ASTAT RETS RETI
,
CYCLES2 EMUDAT
Instruction Length
In the syntax, comment (a) identifies 16-bit instruction length.
Functional Description
The Push instruction stores the contents of a specified register in the
stack. The instruction pre-decrements the Stack Pointer to the next avail-
able location in the stack first. Push and Push Multiple are the only
instructions that perform pre-modify functions.
The stack grows down from high memory to low memory. Consequently,
the decrement operation is used for pushing, and the increment operation
is used for popping values. The Stack Pointer always points to the last
used location. Therefore, the effective address of the push is
The following illustration shows what the stack would look like when a
series of pushes occur.
10-2 ADSP-BF53x/BF56x Blackfin Processor Programming Reference
/* predecrement SP (a) */
, , , ,
FP I3–0 M3–0
, , ,
RETX RETN RETE
, , , and
USP SEQSTAT
, , ,
B3–0 L3–0 A0.X A0.W
, , , ,
LC0 LC1 LT0 LT1
SYSCFG
, , ,
A1.X A1.W
, , , ,
LB0 LB1 CYCLES
.
SP–4