2-7
PENTIUM® PRO PROCESSOR ARCHITECTURE OVERVIEW
2.2.3.
The Retire Unit
Figure 2-6 shows a more detailed view of the Retire Unit.
The retire unit is also checking the status of µops in the instruction pool. It is looking for µops
that have executed and can be removed from the pool. Once removed, the original architectural
target of the µops is written as per the original IA instruction. The retirement unit must not only
notice which µops are complete, it must also re-impose the original program order on them. It
must also do this in the face of interrupts, traps, faults, breakpoints and mispredictions.
The retirement unit must first read the instruction pool to find the potential candidates for retire-
ment and determine which of these candidates are next in the original program order. Then it
writes the results of this cycle’s retirements to both the Instruction Pool and the Retirement Reg-
ister File (RRF). The retirement unit is capable of retiring 3 µops per clock.
2.2.4.
The Bus Interface Unit
Figure 2-7 shows a more detailed view of the Bus Interface Unit.
Figure 2-6. Inside the Retire Unit
RS - Reservation Station
MIU - Memory Interface Unit
RRF - Retirement Register File
R
S
MIU
RRF
From
To
Instruction Pool
To/from DCache
Summary of Contents for Pentium Pro Family
Page 17: ...1 Component Introduction ...
Page 26: ...2 Pentium Pro Processor Architecture Overview ...
Page 27: ......
Page 36: ...3 Bus Overview ...
Page 62: ...4 Bus Protocol ...
Page 105: ...5 Bus Transactions and Operations ...
Page 126: ...6 Range Registers ...
Page 131: ...7 Cache Protocol ...
Page 135: ...8 Data Integrity ...
Page 148: ...9 Configuration ...
Page 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Page 172: ...11 Electrical Specifications ...
Page 201: ...12 GTL Interface Specification ...
Page 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Page 233: ...14 Thermal Specifications ...
Page 239: ...15 Mechanical Specifications ...
Page 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Page 252: ...16 Tools ...
Page 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Page 264: ...17 OverDrive Processor Socket Specification ...
Page 290: ...A Signals Reference ...
Page 320: ...Index ...
Page 328: ......