Ram Sizing
a) How many 256x8 RAM chips are needed to provide a memory capacity of 16,384 bytes?
b) How many lines of the address bus must be used to access 16,384 bytes of memory? How many of these lines will be common to all the chips?
c) Specify the size of the decoder - a decoder is specified as "a x b", where a is the number of lines in, and b is the number of lines out.
© BrainMass Inc. brainmass.com December 24, 2021, 10:05 pm ad1c9bdddfhttps://brainmass.com/computer-science/memory-management/ram-sizing-decoder-442276
SOLUTION This solution is FREE courtesy of BrainMass!
(a) 256x8 RAM chip indicates that RAM chip has 256 8-bit words. In other words it provides 256 bytes of memory.
So, to provide a memory capacity of 16384 bytes, we would require (16384/256) or 64 256x8 RAM chips.
(b) To access 16384 (or 2^14) bytes of memory we would require log-base-2(16384) or 14 lines of the address bus.
Since each of the RAM chips provides 256 (or 2^8) bytes of memory, log-base-2(256) or 8 of these address lines will be common to all the chips.
(c) Since we use (14-8) or 6 non-common address lines to select each one of the 64 RAM chips, we need a 6x64 or 6-to-64 decoder.
© BrainMass Inc. brainmass.com December 24, 2021, 10:05 pm ad1c9bdddf>https://brainmass.com/computer-science/memory-management/ram-sizing-decoder-442276