Marantz PM553 - Page 5

4.
CIRCUIT
DESCRIPTION
Term
SINGLE-CHIP
4-BIT
MICROCOMPUTER
LC6502C
(QU01)
P.
Py
BLOCK
DIAGRAM
Fl
Pi
Pl
pao~3[
PORT
A
és
o-3[_
port
128
X
4BIT
fo
teeee
ese
2048X8BIT
7
Lahey
ee
“ROM
PC
pBo-3[
PORT
B
PC
:
pco-3<_yrorT
cK
_)
=
PD
ee
rg
PE
Fs
PE
pDO-3<
_PORTDK_»
a
RE
TES
ovivs
INT
osc }
osc 2
INT
HOLD
;
RES
This
TEST
ha
-
PGO-3
PHO-3
VoD
ari
vss
Serv
mani
perie
eae)
RAM:
data
memory
ROM:
program
memory
a goc
F:
flag
PC:
program
counter
The
WR:
working
register
INT:
interrupt
control
Most
AC:
accumulator
IR:
instruction
register
Mara
ALU:
logical
operator
unit
1,
DEC:
instruction
decoder
clude’
DP:
data
pointer
CF,
CSF:
carry
flag,
carry
save
flag
E:
E
register
ZF,
ZSF:
zero
flag,
zero
save
flag
CTL:
control
register
EXTF:
external
interrupt
request
flag
‘
OSC:
oscillator
circuit
TMF.
internal
interrupt
request
flag
TM: timer
STS:
status
register
4
3
m5]}