IBM PowerPC 604 User Manual page 266

Reservation
Station
EA
Calculation
Finish
Store
Queue
Complete
Stor_e
Queue
Instruction Flow and Result Bus
Load
Queue
Floating-Point
Convert
FP Convert
Address -
Data -tP--
t
MMU/Cache Interface
Figure 6-17. LSU Block Diagram
Load
Align
The reservation stations are used as temporary storage of dispatched instructions that
cannot
be
executed until all of the instruction operands are valid. The address calculation
block includes a 32-bit adder that computes the effective address for all operations. The
data alignment blocks manage the necessary byte manipulations to support aligned or
unaligned data transfers to and from the data cache. The load and store queues are used for
temporary storage of instructions for which the effective addresses have been translated and
are waiting to
be
completed by the sequencer unit.
6-40 Pow•PC 804 RISC Microproceeaor User's Manual