POPN

POPN De

Restores data register extension pairs, even registers, and loop start registers from the normal stack. Data register extension pairs are popped the same as even numbered registers.

POPN Do

Restores modifier control, odd registers, and loop counter registers from the normal stack.

Status and Conditions that Affect Instruction

Register Address

Bit Name

Description

SR[18]

EXP

Determines execution working mode.

Status and Conditions Changed By Instruction

Register Address

Bit Name

Description

Ln

L

Pops of extensions restore the Ln bit in the destination register. Pops to

 

 

data registers clear the Ln bit.

Example

popn d6.e:d7.e

Register/Memory Address

NSP

$00000008

L6:D6

L7:D7

Before

$00000010

$000000FF

After

$00000008

$0:$FF00000000

$0:$0000000000

Instruction Formats and Opcodes

Instruction

Words

Cycles1

Type

Opcode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

 

 

8

7

 

 

 

 

 

 

0

POPN

De

1

1

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

0

0

1

E

E

E

0

0

0

1

E

0

1

E

1

 

 

 

 

 

15

 

 

 

 

 

 

8

7

 

 

 

 

 

 

0

POPN

Do

1

1

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

0

0

1

e

e

e

1

0

0

1

e

0

1

e

1

Note 1: An extra cycle is added if the shadow SP is not valid when the POP instruction is executed. See Section 5.3.3, “Shadow Stack Pointer Registers.”

Instruction Fields

SC140 DSP Core Reference Manual

A-351

Page 665
Image 665
Freescale Semiconductor SC140 specifications Popn d6.ed7.e, Popn De, Popn Do