Page 371 - FUNDAMENTALS OF COMPUTER

NPP

NPP Memory 371

4.19 Memory Addressing Capability 4.19 grnr¶y H$s ‘o‘moar ES´>oqgJ H¡$no{~{bQ>r
of CPU

Today's CPU is available in the form of a AmO Ho$ g‘¶ grnr¶y qgJb {Mn ‘| CnbãY h¡&
single chip. The maximum amount of main ‘oZ ‘o‘moar H$s A{YH$Va ‘mÌm grnr¶y {Mn na CnpñWV
memory that can be addressed by the CPU
depends on the number of address lines present ES´>og bmBZm| H$s g§»¶m na AmYm[aV hmoVr h¡& CXmhaU
on the CPU chip. For example, if a small CPU Ho$ {bE, EH$ N>moQ>o grnr¶y Ho$ nmg 8 ES´>og bmBÝg h¡&
chip has 8 address lines, it can address 2 8 ¶h 2 =256 ~mBQ²>g h¡& AV… EH$ gm‘mݶ {Z¶‘mZwgma
8
memory locations. Therefore its memory ad-
dressing capability is 2 =256 Bytes. Thus, as a ¶{X grnr¶y na ES´>og bmBZm| H$s g§»¶m N h¡ BgH$s
8
general rule, if N be the number of address line ‘o‘moar ES´>oqgJ H¡$no{~{bQ>r 2 ~mBQ²>g h¡& CXmhaU Ho$
N
on a CPU its memory addressing capability is {bE ‘mBH«$mo àmogoga 8085 ‘| 16 ES´>og bmBÝg h¡,
2 Bytes. For example, in microprocessor 8085
N
16
there are 16 address lines; thus its memory CgH$s ‘o‘moar ES´>oqgJ H¡$no{~{bQ>r 2 ~mBQ²>g (64 Ho$~r)
addressing capability is 2 Bytes (64KB). For a h¡& 32 ES´>og bmBÝg g{hV àmogoga hoVw ‘o‘moar H¡$no{gQ>r
16
processor with 32 address lines the memory 2 (4 Or~r) h¡& AV… ES´>og ~g ‘| {OVZo dm¶am| H$s
32
capacity is 2 (4GB). Thus, as number of wires
32
in the address bus is increased, the memory g§»¶m ~‹T>Vr OmEJr, grnr¶y H$s ‘o‘moar H¡$no{gQ>r ^r ~‹T>
capacity of a CPU also increased. Following Om§EJr& {ZåZ {MÌ ‘| AdYmaUm Xem©B© JB© h¡…
diagram depicts the concepts:

MEMORY
CPU n address lines (max. 2 locations)
n

Memory addressing Capacity of a CPU 
Review Questions

Q.1. Compare Primary and Secondary memory.
àm`_ar VWm goH$ÊS>ar _o_moar H$s VwcZm H$s{OEŸ&
Q.2. What is memory cell? How it is represented? Give different characteristics of memory cell.
_o_moar goc Š`m h¡? Bgo H¡$go àX{e©V {H$`m OmVm h¡? _o_moar goc H$s {d{^ÝZ {deofVmE± ~VmB`oŸ&
Q.3. Explain different types of Primary memory.
àm`_ar _o_moar Ho$ {d{^ÝZ àH$ma g_PmB`oŸ&
Q.4. Explain different types of ROM.
ROM Ho$ {d{^ÝZ àH$ma g_PmB`oŸ&
Q.5. Give difference between Static and Dynamic RAM.
ñQ>o{Q>H$ VWm S>m`Zm{_H$ RAM Ho$ ~rM AÝVa ~VmB`oŸ&