beautypg.com

Push – Texas Instruments TMS320C2XX User Manual

Page 294

background image

Push Low Accumulator Onto Stack

PUSH

7-141

Assembly Language Instructions

Syntax

PUSH

Operands

None

Opcode

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

0

0

1

1

1

1

0

0

0

1

1

1

1

1

0

1

Execution

Increment PC, then...
Push all stack locations down one level
ACC(15:0)

TOS

Status Bits

None

Description

The stack values move down one level. Then, the content of the lower half of
the accumulator is copied onto the top of the hardware stack.

The hardware stack operates as a last-in, first-out stack with eight locations.
If more than eight pushes (due to a CALA, CALL, CC, PSHD, PUSH, TRAP,
INTR, or NMI instruction) occur before a pop, the first data values written are
lost with each succeeding push.

Words

1

Cycles for a Single PUSH Instruction

ROM

DARAM

SARAM

External

1

1

1

1+p

Cycles for a Repeat (RPT) Execution of a PUSH Instruction

ROM

DARAM

SARAM

External

n

n

n

n+p

Example

PUSH

Before Instruction

After Instruction

ACC

X

7h

ACC

X

7h

C

C

Stack

2h

Stack

7h

5h

2h

3h

5h

0h

3h

12h

0h

86h

12h

54h

86h

3Fh

54h

Cycles