Sharp PC-1500 - Page 51

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@ BCH (BranCH)
Ju mps to a new program step w hi ch is indicated by the program counter of wh ich va l ue
is added/ subtracted by the value of the immediate data i .j. It wi ll be po ss ible to jump
within a range
of - 255< i< 255 .
No change tak
es pl ace in flag.~ .
• For mat
RCH+i
BCH
-i
(EX)
BC H+5
Ex ecute
P=4 002H _,
P= 400 7H
•Operati on
p + ; - p
P - i - · P
As soon as th e BCH inst ru cti on is 11e ad ,
t he pr ogram counter be co mes
"P=4 002 H "'. and afte r execut ion of th e
BCH i ns tr uc ti on . th e next program
execu
ti on st a rts f rom the address 410 07H .
® BCS (B ranch if C Set)
Co nd i ti onal re lati ve addr ess jump.
f'----1
-. OCH•
I BCH
r-:;;--
4001H
1 .... 11>,K! <Qn
[I
·-
I-
.. ,"
t-
~
When C= I. it ju mps to a program s te p represe nted by th e program counter of w hi ch
va l ue is added/subtracted wi th the va l ue of the immediate data.
If C=O . the control proceeds di rc clly to a next program step wi thout causing jump.
No ch
an ge ta ke s place in fla g.~ .
•Format
RC S+;
•·Operation
l
l· P + i - P
c- .
0: P not changed.
BCS- i
l
l·P - i - P
c - .
0: P not chan ge d.
(E X) BCS +5
Exe cute
P= 400 2H --> P= 4 007 H
C- 1
As soon as the BCS i ns truction is re ad ,
th e pr ogr am count er bec ome s
"P= 4002 H" . If C=1 at th at po in t. ne xt
pr og ram execu tio n sta rts from t he
ad dr ess 4007H . If C=O. it starts f rom
4 002 H.
•OOOH sc s+ I ac s
~~~ - ~~~~~~
"()( )1 H
5
H I 1nslr "1X tt00
4002H
II C -1
4 006H
'--~~ ~ ~~ ~~ --1
4 007 H
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