Radio Shack TRS-80 Quick Reference Manual page 23

CLR
Cleat.
Accumulator A or B or a mamory location is Ioaded with
OOOOOOOO.
CMP
(8.tllt) Compare Memory Irom Regisler.
~ res
lhe contents of melTlOl'ylocation la the conlents of the
fied
register and sets the appropriale condition codes.
eilher the memory location nor the specified register tS
modilled.
CMP
(16-bil) Compare Memory Irom Register.
Compares the l6-bit contents of the concatenated memory
locatIOns 10 the conlents of
the specifted regisler and sets the
appropriale condition codes. Neither the memory locations nor
the specilied regîster is rnodilied unless autoincremenl or
aulOd8cfemeot are used.
COM
Complement.
Replaces
the contents
01
a memory
kx:ation
Of
accumulator A
Of
B wÎlh ils logical complement. When operating on twos
complement values, all s1gned branches are available.
CWAJ
Clesr CC bits and Wait lOf InterNpl.
This Instruction ANDs an Immediate byte with
the
condition code
register which rnay cleer the interrupl mask bits 1and F, slacks
the entlra machine state on the
hardware stack and then looks
for an Interrupt.
DM
DecImal Addition Adjust.
The
sequence of a single-byte add instruction on aCOJmulator A
and IOftowing decimal addiUon adjust instruction resulls in a
BCD
addition with an appropriate cany
bit.
DEC
0"'''"',,,,,,-
SUbtraets
one
tram
the
operand.
The cany bit is not affected.,
thU$ allowing lt1is instruction to
be used as a Ioop counter in
multiple-precision computations.
EOR
Exclusive
OR.
The contents of a memory location is exclusive ORed into an
a·bit register.
EQD
Inltlallzes data or addresses and sets up a label. EaU
commands may
be
Iocated anywhere in the program.
EXG
Exchange
Registers.
Exctlanges
data betweeo Iwo
designated fegisters.
FCB
Form Constant Byte.
Inserts
one
byte of data at
this
point in
!he
program.
FCC
Form Constant Charaeter.
Writes an ASCII strif'l!';l iota memory, using the synlaX:
label
FCC
de/imiter string de/imIter.
INC
Increment.
Adds tothe operand. The carry bit is not affeeted, thus allowing
this instruction to be used as a loop counter in multiple·precision
computations.
'MP
Jump.
Program control is translerred to the elfective address.
>SR
Jumpto Subroutine.
Pn:19ram controlls translerred to the elfecüve address after
stonng
the retum address
on
the stade
LD
(6-bit) load Register frcm
Memory.
loads the contents of a memory location into the designated
register.
LD
(16·bit) load Reglster from Memory.
Loads the contents of the memmy locations into the designated
16·bit register.
UA
Load
Elfective Address. •
Cak:ulates the effective address Irom the inclexed addressing
mode and places
the
address in
an
inclexable register.
LSL
~
Shift
left.
Shifts all
bits
of accumulalof A
or
B
or a memory location one
place
10 the 19ft. Bit
zem is Ioaded
with
a zero.
Bit sevan
of
ac:cumulator A
or
B
or
the memory
Iocalion is
shifted into the C
(carry) bit.
LSR
Logical Shift RighI.
Performs a lagicsl shift right on the operand. Shifls a zero into bit
seven and bit zero into the
C
(carry) bil.
MDL
Multiply.
Multiply the unsigned binary numbers in the accumulators and
place the result in bath accumulalors. Unsigned multiply altows
multiple..precision operations.
- - - - - - - - - - - " " ' ' t
,
42