1. How many segments exist in a 2MB memory if you know that each
segment of size 64KB
No. of segment =size of memory / size of one segment
= 221 / 216 = 25
2. 2. What is the maximum size of the main memory if the microprocessor
has 32 address pins ?
Maximum size=232
3. A microprocessor has a main memory of 16K X 8 and a cache memory of 2K
X 8. Using direct mapping , what will be the size of the tag field ?
Main memory size= 214 –>> address size of main memory= 14 bits
Cache size= 211 >>> address size of cache = 11 bits
Index field size= cache address size= 11 bits
Tag field size= memory address size- cache memory size
= 14 – 11
= 3 bits
4. A microprocessor has a main memory of 16K X 8 and a cache memory of 2K
X 8. Using set associative mapping with set size of 3 , what will be the size
of each cache memory word?
Memory word= No. of sets(tag size + data size)
= 3(3+8)
tag size computed from q3.
=33 bits
according to the following figure
A block diagram of 256 X 8 RAM used to design 4K X 8 system
RAM
256 X 8
CS1
CS2
8
5. How many memory chips require to design 4k X 8 system using the above
memory chip?
16 chips = memory size/ chip size =(212/28)
6. Assume that the microprocessor can directly address 64K,using linear
decoding and don't care conditions as 1's, what will be the memory map for
the first chip, assume there is one chip.
1-can address 64k (216)>>>> the address size is 16 bit
2- according to memory chip design the address size is 8 bit (256=28)
3-so the address range (memory map) will be:
From:
1111 1110 0000 0000
First address in the chip
Chip select cs1 – in this case only one chip so the other chips
will be don’t care
Don’t care
Until : 1111 1110 1111 1111
Last address in the chip
7. Using full decoding what will be the size of the decoder?
4 bits will allow selection of 16 options.
4x16 tutorial
8. Assume that the microprocessor can directly address 64K,using full decoding
and don't care conditions as 1's, what will be the memory map for the first
chip, if you use the CS2 signal for M/IO
9. A microprocessor has a main memory of 1k x 32 and a cache memory of 512
x 32. Using direct mapping, determine the sizes of the tag field, index field,
and each word of the cache
Word size=32
Index size= 9
Tag size= m-n>> 10-9=1
10.A microprocessor with 20 address pins and eight data pins is connected to
two 1k x 8 memory chips with one chip enable for each chip.
a. How many unused address bits of the microprocessor if using linear
decoding technique?
20 bit address : 10 bit used for chip address and 2 bit chip select
20-12=8 unused bits
b. Using linear decoding and don’t care conditions as 0’s, determine the
memory map in hexadecimal.
Chip1: 0080-00BFF
Chip2:00400-007FF
11.Given a memory with 12 bits address and an 8-bit word size.
a. How many bytes can be stored in this memory?
b. If this memory were constructed from 1k x 8 RAMS, how many
memory chips would be required ?
c. What will be the size of the decoder if this memory has full decoding
technique? (note: use 16 bits microprocessor)