Operations:

Syntax:

Operation:

Operands:

Program Counter:

Opcode

Comment

Stack

CBR Rd,K

Rd = Rd AND (0xFF - K)

16 <= d <= 31, 0 <= K <= 255

PC = PC + 1

16-bit Opcode: (see ANDI with K complemented)

Description

Clears the specified bits in register Rd. Performs the logical AND between the contents of register Rd and the complement of the constant mask K. The result will be placed in register Rd. (Equivalent to ANDI Rd,(0xFF - K).)

Status Register (SREG) and Boolean Formula

I

–

T

–

H

–

S

⇔

N XOR V, for signed tests.

V

0

0

Cleared.

N

⇔

R7

Set if MSB of the result is set; cleared otherwise.

Z

⇔

~R7 AND ~R6 AND ~R5 AND ~R4 AND ~R3 AND ~R2 AND ~R1 AND ~R0

Set if the result is 0x00; cleared otherwise.

C

–

R (Result)

R (Result) equals Rd after the operation.

Example: 

      cbr   r16,0xF0  ; Clear upper nibble of r16
      cbr   r18,1     ; Clear bit 0 in r18

Words

1 (2 bytes)

Table Cycles

Name

Cycles

AVRe

1

AVRxm

1

AVRxt

1

AVRrc

1