INSTRUCTION GROUPS

 

 

 

 

 

 

 

DO

#n1,END1

 

 

 

 

 

 

 

 

 

 

 

 

 

:

 

 

 

 

 

 

 

 

 

DO

#n2,END2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

:

 

 

 

 

 

 

 

 

 

 

:

 

 

 

 

 

 

 

 

 

MOVE

 

A,X:(R0)+

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

END2

ADD

A,B

X:(R1)+,X0

 

 

 

 

 

 

 

END1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6-14 Nested DO Loops

6.4.5 Move Instructions

The move instructions perform data movement over the XDB and YDB or over the GDB. Move instructions only affect the CCR bits S and L The S bit is affected if data growth is detected when the A or B registers are moved onto the bus. The L bit is affected if limiting is performed when reading a data ALU accumulator register. An address ALU instruction (LUA) is also included in the following move instructions. The MOVE instruction is the par- allel move with a data ALU no-operation (NOP).

LUA

Load Updated Address

MOVE

Move Data Register

MOVEC

Move Control Register

MOVEM

Move Program Memory

MOVEP

Move Peripheral Data

Note: Due to instruction pipelining, if an AGU register (Mn, Nn, or Rn) is directly changed with a MOVE-type instruction, the new contents may not be available for use until the sec- ond following instruction. See the restrictions discussed in SECTION 7 - PROCESSING STATES on page 7-10.

There are nine classifications of parallel data moves between registers and memory. Fig- ure 6-15shows seven parallel moves. The source of the data to be moved and the destination are separated by a comma.

Examples of the other two classifications, XY and long (L) moves, are shown in Figure 6-

16.Example A illustrates the following steps: 1) register X0 is added to register A and the result is placed in register A; 2) register X0 is moved to the X memory register location pointed to by R3, and R3 is incremented; and 3) the contents of the Y memory location pointed to by R7 is moved to the B register, and R7 is decremented.

Example B depicts the following sequence: 1) register X0 is added to register A and the result is placed in register A; and 2) registers A and B are moved, respectively, to the loca-

MOTOROLA

INSTRUCTION SET INTRODUCTION

6 - 27

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Motorola DSP56000, 24-Bit Digital Signal Processor manual Lua, Movec, Movem, Movep