AN2203 Freescale Semiconductor / Motorola, AN2203 Datasheet - Page 4

• Manufacturer Part Number: AN2203
• Description: MPC7450 RISC Microprocessor Family Software Optimization Guide
• Manufacturer: Freescale Semiconductor / Motorola

High-Level Differences
Part II
Processor Overview
This section describes the high-level differences between the MPC750, MPC7400, and MPC7450. Also, it
describes the pipeline differences for these three processors.
2.1
To achieve a higher frequency, the MPC7450 design reduces the number of logic levels per cycle, which
extends the pipeline. More resources were added to reduce the effect of the pipeline length on performance.
These pipeline length and resource changes can make an important difference in code scheduling. Table 2-1
describes high-level differences between MPC750, MPC7400, and MPC7450 processors.
4
Logic inversions per cycle
Pipeline stages up to first execute
Minimum total pipeline length
Pipeline maximum instruction throughput
Instruction queue size
Completion queue size
Rename register (integer, vector, FP)
Branch prediction structures
BTIC size, associativity
BTIC instructions/entry
BHT size
Link stack depth
Unresolved branches supported
Branch taken penalty (BTIC hit)
Minimum branch mispredict penalty (cycles)
Integer execution units
Floating-point execution units
Vector execution units
Microprocessor Feature
High-Level Differences
MPC7450 RISC Microprocessor Family Software Optimization Guide
Freescale Semiconductor, Inc.
For More Information On This Product,
Branch Prediction Resources/Features
Table 2-1. High-Level Differences
Go to: www.freescale.com
Available Execution Units
Basic Pipeline Functions
Pipeline Resources
1 double-precision
1 IU1, 1 IU1/IU2,
64-entry, 4-way
2 + 1 branch
BTIC, BHT
512-entry
MPC750
6, N/A, 6
1 SRU,
1 LSU
FPU
N/A
N/A
28
3
4
6
6
2
2
0
4
2-issue to VPU and
VSIU, VCIU, VFPU
1 double-precision
1 IU1, 1 IU1/IU2,
VALU (VALU has
64-entry, 4-way
2 + 1 branch
BTIC, BHT
MPC7400
512-entry
subunits)
1 SRU,
1 LSU
6, 6, 6
FPU
N/A
28
3
4
6
8
2
2
0
4
BTIC, BHT, LinkStack
2 vector units (VSIU,
VPU, VCIU, VFPU)
1 double-precision
128-entry, 4-way
2-issue to any
3 + 1 branch
1 IU2/SRU,
2048-entry
MPC7450
16, 16, 16
1 LSU
3 IU1,
FPU
MOTOROLA
18
12
16
5
7
4
8
3
1
6