Page 389 - FUNDAMENTALS OF COMPUTER

NPP

NPP CPU Architecture, Addressing Modes and Data Transfer Schemes 389

 r and r can be any 16-bit data registers. · r Ed§ r H$moB© ^r 16-{~Q> a{OñQ>g© hmo gH$Vo h¢,
1
2
2
1
e.g. AWm©V²
MOV AX, BX
 Any one can be segment register. e.g. · H$moB© ^r EH$ goJ_|Q> a{OñQ>a hmo gH$Vm h¡ AWm©V²
MOV DS, AX
 Register can also be any general register- · a{OñQ>a H$moB© ^r OZac a{OñQ>a- AWm©V² SI, DI,
e.g. SI, DI, SP, BP, etc. e.g. SP, BP Am{X hmo gH$Vm h¢ AWm©V²

MOV BP, SP
MOV SI, AX
 Both registers cannot be segment regis- · XmoZm| a{OñQ>g© goJ_|Q> a{OñQ>g© Zht hmo gH$Vo&
ters.

 r is called source Register and r is called · r H$mo gmog© a{OñQ>a H$h|Jo VWm r H$mo S>opñQ>ZoeZ
1
2
1
2
destination register. The content of source a{OñQ>a H$h|Jo& gmog© a{OñQ>a r Ho$ H§$Q>|Q> `WmdV²
register r remain unchanged. The data 2
2
transfer instruction may be represented An[adV©Zr` ah|Jo& S>mQ>m Q´>m§g\$a B§ñQ´>ŠeZ H$mo Bg
as: àH$ma {XIm`m OmEJm:
(r ) (r )
2
1
MOV r, data: Transfer the datum into the MOV r, data: ñno{g\$mBS> a{OñQ>a ‘| S>oQ>_ Q´>m§g\$a
specified register source has Immediate ad- H$a|& gmog© H$m ‘moS> B‘r{S>EQ> h¡&
dressing mode.
 Register r can be any 8 bit or 16 bit general · a{OñQ>a r 8-{~Q> `m 16-{~Q> OZac a{OñQ>a hmo
register. e.g. gH$Vm h¡ O¡go…
MOV AL, 42H
MOV AX, 4050H
 Register r cannot be a segment register. · a{OñQ>a r goJ_|Q> a{OñQ>a Zht hmo gH$Vm h¡& goJ_|Q>
The segment register can not be used with a{OñQ>a H$m B_r{S>EQ> Am°na|S> Ho$ gmW Cn`moJ Zht
immediate operand. Thus MOV DS, 41F2H hmo gH$Vm h¡& Bg{cE MOV DS, 41F2H H$s AZw_{V
is not allowed.
Zht h¡&
MOV r, m: Transfer contents of memory MOV r, m: a{OñQ>a r _| _o_moar cmoHo$eZ m Ho$
location m into register r. Here memory loca- H§$Q>|Q²>g Q´>m§g\$a H$a|& S>mQ>m goJ_|Q> _| _o_moar cmoHo$eZ m
tion m specify offset in the data segment.
Am°\$goQ> h¡&
 Register can be any 8-bit register. In that · a{OñQ>a H$moB© ^r 8-{~Q> a{OñQ>a hmo gH$Vm h¡& Cg
case memory m automatically points to a Xem _| m _o_moar S>mQ>m goJ_|Q> Ho$ A§Xa ~mBQ> na
byte in the data segment:
Am°Q>mo_o{Q>H$cr nm°B§Q> AmCQ> hmoJm&
MOV AH, [BX]