Rev. 1.50, 10/04, page 56 of 448
4.3
Issue Rates and Execution Cycles
Instruction execution cycles are summarized in table 4.4. Instruction Group in the table 4.4
corresponds to the category in the table 4.2. Penalty cycles due to a pipeline stall are not
considered in the issue rates and execution cycles in this section.
1. Issue Rate
I1
I2
ID
S1
S2
S3
WB
Issue rate: 3
E2S2
E3S3
WB
Issue rates indicates the issue period between one instruction and next instruction.
E.g. AND.B instruction
E1S1
I1
I2
ID
S1
S2
S3
WB
MS
S2
S3
WB
S1
ID
ID
ID
(I1)
(ID)
(I2)
Next instruction
M3
M2
Issue rate: 2
(I1)
(ID)
(I2)
E.g. MAC.W instruction
Execution cycles indicates the cycle counts an instruction occupied the pipeline based on the next rules.
CPU instruction
E.g. AND.B instruction
I1
I2
ID
S1
S2
S3
WB
Execution Cycles: 3
E2S2
E3S3
WB
E1S1
ID
ID
I1
I2
ID
S1
S2
S3
WB
MS
S2
S3
WB
S1
ID
M3
M2
E.g. MAC.W instruction
Execution Cycles: 4
2. Execution Cycles
Next instruction
FPU instruction
E.g. FMUL instruction
Execution Cycles: 14
E.g. FDIV instruction
FE1
FE2
FE3
FE4
FE5
FE6
FE1 FE2 FE3 FE4 FE5 FE6
FS
FE1
FE2
FE3
FE4
FE5
FE6
FS
FE1
FE2
FE3
FE4
FE5
FE6
FS
I1
I2
ID
I1
I2
ID
Divider occupation cycle
FS
FE3 FE4 FE5 FE6
FS
Execution Cycles: 3
Содержание SuperH SH-4A
Страница 2: ...Rev 1 50 10 04 page ii of xx ...
Страница 8: ...Rev 1 50 10 04 page viii of xx ...
Страница 116: ...Rev 1 50 10 04 page 96 of 448 ...
Страница 178: ...Rev 1 50 10 04 page 158 of 448 ...
Страница 206: ...Rev 1 50 10 04 page 186 of 448 ...
Страница 231: ...Rev 1 50 10 04 page 211 of 448 Possible Exceptions Slot illegal instruction exception ...
Страница 235: ...Rev 1 50 10 04 page 215 of 448 Possible Exceptions Slot illegal instruction exception ...
Страница 238: ...Rev 1 50 10 04 page 218 of 448 Possible Exceptions Slot illegal instruction exception ...
Страница 408: ...Rev 1 50 10 04 page 388 of 448 Possible Exceptions Inexact Not generated when FPSCR PR 1 ...
Страница 445: ...Rev 1 50 10 04 page 425 of 448 Possible Exceptions Invalid operation Overflow Underflow Inexact ...
Страница 446: ...Rev 1 50 10 04 page 426 of 448 ...
Страница 468: ...Rev 1 50 10 04 page 448 of 448 ...
Страница 471: ......
Страница 472: ...SH 4A Software Manual ...