Pipeline Execution of Instruction Types

Figure 4−13. Store Instruction Execution Block Diagram

E2

Functional

unit

.D

E1

Register file

Data

Memory controller

Memory

E2

Address E3

When you perform a load and a store to the same memory location, these rules apply (i = cycle):

-When a load is executed before a store, the old value is loaded and the new value is stored.

iLDW

i + 1

STW

-When a store is executed before a load, the new value is stored and the

new value is loaded.

iSTW

i + 1

LDW

-When the instructions are executed in parallel, the old value is loaded first and then the new value is stored, but both occur in the same phase.

iSTW

i

LDW

SPRU733

Pipeline

4-19

Page 351
Image 351
Texas Instruments TMS320C67X/C67X+ DSP manual 13. Store Instruction Execution Block Diagram