Figure 6–13. Store Execution Block Diagram
E2
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
There is additional explanation of why stores have zero delay slots in section
6.3.8.
Functional
unit
.D
E1
Register file
Data
Memory controller
Memory
Functional Unit Hazards
E2
Address
E3
TMS320C67x Pipeline
6-41