mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 156

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

The PowerPC Core
To execute multiple (lmw, stmw) instructions, string instructions, and unaligned accesses,
the load/store unit contains an address incrementor that generates the needed addresses.
This allows the unit to execute the unaligned accesses without stalling the master instruction
pipeline.
6.6.1 Issuing Load/Store Instructions
When load or store instructions are encountered, the load/store unit checks the scoreboard
to determine if all of the operands are available. These operands include:
If all operands are available, the load/store unit takes the instruction and enables the
sequencer to issue a new instruction. Then, using a dedicated interface, the load/store unit
notifies the integer unit of the need to calculate the effective address. All load/store
instructions are executed and terminated in order.
• Address register operands
• Source data register operands (for store instructions)
• Destination data register operands (for load instructions)
• Destination address register operands (for load/store with update instructions)
INCREMENT
ADDRESS
ADDRESS
QUEUE
FIXED-POINT
AND
Figure 6-6. Load/Store Unit Functional Block Diagram
UNIT
Freescale Semiconductor, Inc.
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For More Information On This Product,
LOAD / STORE UNIT
MPC823 REFERENCE MANUAL
REGISTERS FILE
32
FIXED-POINT
Go to: www.freescale.com
LOAD DATA
D-CACHE / D-MMU
FIXED-POINT
INTERFACE
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FIXED-POINT
QUEUE
DATA
CORE
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FIXED-POINT
STORE DATA
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MOTOROLA