Pipeline Execution of Instruction Types
4-19PipelineSPRU733
Figure 4−13. Store Instruction Execution Block Diagram
Memory
E2
E3
Memory controller
Register file
E1
.D
Data
E2
Address
Functional
unit
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.
i LDW
i + 1 STW
When a store is executed before a load, the new value is stored and the
new value is loaded.
i STW
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.
i STW
i || LDW
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