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memory of the USB devices in power 2? -
why memory of usb devices in powers of 2?
because memory devices array of bytes or words. such there address (index) , data both binary numbers. 1 megabyte memory have 20 bit address "bus" , 8 bit data bus. these buses physically constructed 1 electrical conductor per bit, 1meg device have 20 address pins , 8 data pins. in dram, there may multiplexing, half of address sent on 1 clock cycle , other half on clock cycle - can reduce number of physical pins , traces on circuit board. making 2meg memory out of such chips easy, connect address , data pins , use "chip select" pin determine 1 being accessed via 21st address bit. partitioning memory in non-power-of-2 scheme requires lot more circuitry , interconnection complexity figure out chip data in, , means not using every bit combination of address lines mean less efficient use of circuitry.
hope helps.
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