L1. Introduction Flashcards
How can we measure efficiency?
Instructions/second
How can we convert battery capacity from mAH (charge) to joules (energy) we have the voltage?
Charge * voltage = energy
How are joules and watts related?
1 W /s = 1 J
Name 5 mobile phone features?
- CALLS (cell or wifi)
- Data & internet access
- Sound & Image capture (stored & comm)
- Bluetooth & NFC
- GPS (navigation satellite)
Why are general purpose processors used in PCs & laptops not used in smartphones?
BIG POWER CONSUMPTION
What kinda processors are used in phones?
RISC
Name four types of system memory in phones
Flash-storage/os
ROM -manufacturer, permanent
DRAM
SRAM
Which is faster SRAM or DRAM?
SRAM
What is a special difference between DRAM and SRAM
DRAM needs to be constantly refreshed
Is more RAM always better?
Not necessarily, uses more BATTERY POWER
Reasons why smartphones have evolved?
- Moore’s law (cost,power,weight)
- OS & Apps
- Media processing & compression
- Communications (+error correction)
- Batteries and their use
What theorem must we follow when selecting the sampling rate Fs for sound waveforms. What happens if we don’t follow this?
- Sampling Theorem Fs > 2 x F (max freq of wave)
- aliasing distortion
