Question

1. Give around 7 examples of where you would find embedded computers. These can be at home or at school even work.

2. Say you are a CIO of some sort of firm, what factors would you consider when you are selecting secondary storage media for your companys records?

3. Which is faster and why? CPU to Cache communication or CPU to RAM communication

Answer 1

1. Example of embedded computers:

1. Mobile phone
2. Engine sensor, ABS brake in an automobile
3. Vending machine
4. Video game console
5. Network devices like switch, modem, router
6. Digital camera
7. Calculator

2. Considerations for selecting secondary storage:

1. read/write speed (I/O speed) of the medium. the faster the I/O the better, because less time is wasted waiting for the data transfer to happen
2. reliability of the medium. the storage type should be able to retain data for long period of time, without corrupting it.
3. cost of storing per unit of data. some drives are costlier (SSD) than the others (HDD), but provide better speed and/or reliability

3. CPU to cache communication is faster than CPU to RAM communication. The cache is embedded in the CPU (assuming L1 cache here; in some cases L2 cache too is embedded in the CPU chip), hence, it takes less time to access the cache than RAM. According to some benchmarks, L1 access takes about 2 ns, compared to 60 ns for accessing RAM.

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