This document discusses embedded systems and strategies for improving their performance and efficiency. It describes embedded systems as low-power, fast, task-specific, reliable, and inexpensive systems like microcontrollers. It then discusses ways to reduce power consumption by lowering voltage and frequency or reducing unnecessary hardware states. It also explores techniques for improving speed like pipelining, branch prediction, speculation, and using shorter instructions. Finally, it notes that simplifying hardware can improve throughput and power but that software must then handle more complexity.

1. 1

2. Embeded systems
Future architecture
Mohammad Amin Khorsandi
2

3. What are embedded systems?
1- Low power
2- Fast (critical throughput)
3- Particular task
4- Reliable
5- Cheap
6- Small size
Applications:
3

4. Platforms:
 Microcontrollers
 Microprocessors
 FPGA
 Digital signal processors
 Application specific integrated circuits
4

5. 5
Power consumption reduction
Power is influenced by voltage and
pulses on each part of hardware
Traditional idea:
Reducing voltage and frequency if
necessary

6. 6
Power consumption reduction
New idea
reducing hardware to obtain the least
states between instructions, data and
functional units.
Instruction>>
Pipeline, branch prediction, memory
access, speculation and etc.
>>function unit

7. Fast? How come? How much?
7

8. worst-case of execution time
Pipeline (hazards and stages)
Speculation
events
Branch miss prediction
Cache miss
Computing maximum band of execution time:
Exclude as many possible timing accident
8

9. 9
Shorter instructions

10. Cache
The most important consideration for
cache speedup is predictability.
May: upper approximations of cache content
Must: lower approximations of cache content
Evict: when “may” information becomes
available
Fill: when “must” and “may” information is
obtained
10

11. 11
Predictability of k-way LRU/PLRU/FIFO

12. 12
Multicores
 Not highly recommended
 Avoiding shared resources conflict
 Using crossbars for communication
between shared resources
 Private L1 and L2 replacement
strategies

13. 13
Conclusion
 Simplifying the hardware causes
increasing in critical throughput and
power saving
 We must take care of these
simplicities
 Software must carry the burden of
simplicity in hardware.