EXT Instruction

Purpose:

To copy a bit field to a long word

Format:

opcode startpos.rl, size.rb, base.vb, dst.wl

Operation:

EXTV: dst <- sign-extended {extracted field}
EXTZV: dst <- zero-extended {extracted field}

Condition
Codes:

N <- dst LSS 0;
Z <- dst EQL 0
V <- 0;
C <- 0;

Exceptions:

Reserved Operand

Opcodes:

EE	EXTV	Extract Field
EF	EXTZV	Extract Zero-extended Field

Description:

For EXTV, the destination operand is replaced by the sign-extended field specified by the position, size and base operands. For EXTZV, the destination is replaced by the zero-extended field. If the size operand is 0, the action is to replace the destination with 0 and effect the condition codes.

Notes:

1.: A reserved operand fault occurs if the unsigned size operand is greater than 32 or the bit field is contained in a register and the position operand is outside the range 0 - 31.
2.: On a reserved operand fault, the destination is unaffected and the condition codes are unpredictable.
3.: If the base address is a register, the bit field may extend into the next register.
4.: The startpos operand may be negative.