BMCLR;Instruction Set:BMCLR

BMCLR Bit-Masked Clear a 16-Bit Operand (BMU) BMCLR

Operation

Assembler Syntax

 

 

 

0 → C1.Hi (i denotes bits=1 in #u16)

BMCLR #u16,C1.H

{0

u16 < 216}

0

→ C1.Li

BMCLR #u16,C1.L

{0

u16

< 216}

0

→ DR.Hi

BMCLR

#u16,DR.H

{0

u16

<

216}

0

→ DR.Li

BMCLR

#u16,DR.L

{0

u16

<

216}

Description

These operations use an unsigned 16-bit immediate data mask to clear selected bits in the destination operand. For each bit i that is set (selected) in the mask, the bit i in the corresponding destination operand’s bit position is cleared. Bits that are not selected as well as bits in the other part of the register are unaffected. These operations read from a register, modify the retrieved value, and write the new value back to that register.

Note: Special care must be taken when using this instruction to clear bits on the EMR register due to this register’s special functionality. See Chapter 3 for a description of this behavior.

BMCLR #u16,C1.H

Clears selected bits in the HP contents of a control register (C1).

BMCLR #u16,C1.L

Clears selected bits in the LP contents of a control register (C1).

BMCLR #u16,DR.H

Clears selected bits in the HP contents of a data or address register (DR).

BMCLR #u16,DR.L

Clears selected bits in the LP contents of a data or address register (DR).

Status and Conditions that Affect Instruction

Register Address

Bit Name

Description

SR[18]

EXP

Determines execution working mode for instructions that have these

 

 

registers as an operand.

SC140 DSP Core Reference Manual

A-75

Page 389
Image 389
Freescale Semiconductor SC140 specifications Bmclr Bit-Masked Clear a 16-Bit Operand BMU Bmclr Operation, Bmclr #u16,C1.H