RX610 Group
2. CPU
R01UH0032EJ0120 Rev.1.20
Page 85 of 1006
Feb 20, 2013
IF
D
E
MOV [R2], R1
M
WB
IF
D
stall
E
WB
ADD R2, R1
Bypass process
(mop) load
(mop) add
Figure 2.23 When the Subsequent Instruction Uses an Operand Read from the Memory
(2)
Pipeline Flow with no Stall
(a)
Bypass process
Even when the result of the preceding instruction will be used in a subsequent instruction, the operation processing
between registers is pipelined in by the bypass process.
IF
D
E
ADD R1, R2
SUB R3, R2
WB
IF
D
E
WB
Bypass process
(mop) add
(mop) sub
Figure 2.24 Bypass Process
(b)
When WB stages for the memory load and for the operation are overlapped
Even when the WB stages for the memory load and for the operation are overlapped, the operation processing is
pipelined in, because the load data and the operation result can be written to the register at the same timing.
IF
D
E
MOV [R1], R2
IF
D
E
WB
ADD R5, R3
M
WB
(mop) add
(mop) load
Executed at the same timing
even when the WB stages are
overlapped
Figure 2.25 When WB Stages for the Memory Load and for the Operation are Overlapped