Motorola 24-Bit Digital Signal Processor, DSP56000 manual Movec LC,X0 move LC into

INSTRUCTION DESCRIPTIONS

MOVEC

Move Control Register

MOVEC

A MOVEC instruction which specifies SSH as the source operand or LA, LC, SSH, SSL, or SP as the destination operand cannot be used immediately before a DO instruc- tion.

A MOVEC instruction which specifies SSH as the source operand or LA, LC, SR, SSH, SSL, or SP as the destination operand cannot be used immediately before an ENDDO instruction.

A MOVEC instruction which specifies SSH as the source operand or SR, SSH, SSL, or SP as the destination operand cannot be used immediately before an RTI instruction.

A MOVEC instruction which specifies SSH as the source operand or SSH, SSL, or SP as the destination operand cannot be used immediately before an RTS instruction.

A MOVEC instruction which specified SP as the destination operand cannot be used immediately before a MOVEC, MOVEM, or MOVEP instruction which specifies SSH or SSL as the source operand.

A MOVEC SSH, SSH instruction is illegal and cannot be used.

Example:

:

MOVEC LC,X0 ;move LC into X0

:

LC

Before Execution

$0100

LC

After Execution

$0100

X0

$123456

X0

$000100

Explanation of Example: Prior to execution, the 16-bit loop counter (LC) register con- tains the value $0100, and the 24-bit X0 register contains the value $123456. The execu- tion of the MOVEC LC,X0 instruction moves the contents of the 16-bit LC register into the 16 LS bits of the 24-bit X0 register and zeros the 8 MS bits of the X0 register.

A - 208 INSTRUCTION SET DETAILS MOTOROLA