beautypg.com

Cala – Texas Instruments TMS320C2XX User Manual

Page 211

background image

CALA

Call Subroutine at Location Specified by Accumulator

7-58

Syntax

CALA

Operands

None

Opcode

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

0

0

0

0

1

1

0

0

0

1

1

1

1

1

0

1

Execution

PC + 1

TOS

ACC(15:0)

PC

Status Bits

None

Description

The current program counter (PC) is incremented and pushed onto the top of
the stack (TOS). Then, the contents of the lower half of the accumulator are
loaded into the PC. Execution continues at this address.

The CALA instruction is used to perform computed subroutine calls.

Words

1

Cycles for a Single CALA Instruction

ROM

DARAM

SARAM

External

4

4

4

4+3p

Note:

When this instruction reaches the execute phase of the pipeline, two additional instruc-
tion words have entered the pipeline. When the PC discontinuity is taken, these two
instruction words are discarded.

Example

CALA

Before Instruction

After Instruction

PC

25h

PC

83h

ACC

83h

ACC

83h

TOS

100h

TOS

26h

Cycles