Read Sharp UP-3300 (serv.man13) Service Manual online
2-1-4. Overcurrent monitor circuit
1) The pin-6 of the comparator IC4 is the overcurrent monitor input.
2) If the Q1 driving current increased and the voltage across R48
becomes above 0.6V, the comparator IC4 output turns on and its
level goes low and the voltage at
level goes low and the voltage at
B
turn low.So, Q1 turns off by
the feedback circuit.
2-2. Display control
2-2-1. CKDC9 (HD4728B02FS)
1) General description
The CKDC9 is a 4-bit microcomputer developed for the POS and
provides functions to control the real-time clock, keys, and displays.
The basic functions of the CKDC9 are shown below.
provides functions to control the real-time clock, keys, and displays.
The basic functions of the CKDC9 are shown below.
Keys:
The CKDC9 is capable of controlling a maximum of 256
momentary keys. (Sharp 2-key rollover control)
momentary keys. (Sharp 2-key rollover control)
Simultaneous scanning of key and switch
(When a key is scanned, the state of a mode and clerk
switch is also buffered. The host can scan the state of
switch together with the key entry data at the same time
the key is scanned.)
(When a key is scanned, the state of a mode and clerk
switch is also buffered. The host can scan the state of
switch together with the key entry data at the same time
the key is scanned.)
Switches:
Mode switch with 14 positions maximum
8-bit clerk (cashier) switch2-bit feed switch
1-bit receipt on/off switch
1-bit receipt on/off switch
1-bit option switch
4-bit general-purpose switch (1-bit is used for keyboard
select)
select)
Displays:
16-column dot display
12-column 7-segment display (column digit selectable)
All column blink controlled for the dot and 7-segment
display decimal point and indicators
display decimal point and indicators
Programmable patterns for 7-segment display:
Four patterns
Internal driver for 7-segment display
Buzzer:
Single tone control
Clock:
Year, month, day of month, day of week, hour, minute,
second
second
Alarm:
Hour, minute
Interrupt request (event control):
Detection of key input, switch position change, alarm
issue, and counter overflow
issue, and counter overflow
2) Pin assignment
Pin
No.
No.
Port
I/O
RESET
State
Signal
name
I/O
Notes
PULL
−
UP
−
DOWN
1
R0
1
I/O
H-Z
SB
O
DB4 : SEG-B
PULL-DOWN
2
R0
2
I/O
H-Z
SC
O
DB4 : SEG-C
PULL-DOWN
3
R0
3
I/O
H-Z
SD
O
DB4 : SEG-D
PULL-DOWN
4
R1
0
I/O
H-Z
SF
O
DB4 : SEG-E
PULL-DOWN
5
R1
1
I/O
H-Z
SE
O
DB4 : SEG-F
PULL-DOWN
6
R1
2
I/O
H-Z
SG
O
DB4 : SEG-G
PULL-DOWN
7
R1
3
I/O
H-Z
P4
O
DB7 : 7SEG COM
PULL-DOWN
8
R2
0
I/O
H-Z
P0
O
DB2 : DOT DP : NU
PULL-DOWN
9
R2
1
I/O
H-Z
P1
O
DB3 : DOT COM : NU
PULL-DOWN
10
R2
2
I/O
H-Z
P2
O
DB5 : 7SEG DP
PULL-DOWN
11
R2
3
I/O
H-Z
P3
O
DB5 : 7SEG ID
PULL-DOWN
12
RA
0
I
I
MODR
I
MODE RETURN : NU
PULL-UP
13
RA
1
I
I
CFSR
I
CASHIER, PAPER
FEED SWITCH : NU
RETURN
FEED SWITCH : NU
RETURN
PULL-UP
14
R3
0
I/O
H-Z
KEX0
O
KEY EXCHANGE0 : NU
15
R3
1
I/O
H-Z
KEX1
O
KEY EXCHANGE1 : NU
16
R3
2
I/O
H-Z
RQ
O
INPUT Q : NU
17
R3
3
I/O
H-Z
SKR0
O
kEY SELECTO : NU
18
R5
0
I/O
I
ST0
O
KEY SCAN ST0 : NU
19
R5
1
I/O
I
ST1
O
KEY SCAN ST1 : NU
20
R5
2
I/O
I
ST2
O
KEY SCAN ST2 : NU
21
R5
3
I/O
I
ST3
O
KEY SCAN ST3 : NU
22
R6
0
/INT0 I/O
I
POFF
I
P-OFF : NU
23
R6
1
/INT1 I/O
I
STOP
I
STOP : NU
PULL-UP
24
R6
2
/INT2 I/O
I
DDIG
O
DOT DISPLAY DIGIT INPUT : NU
25
R6
3
/INT3 I/O
I
DCS
O
DOT DISPLAY CONT./CS : NU
26
Vcc
Power supply
27
R4
0
/SCK
I/O
I
SCK
I
SCK
28
R4
1
/SI
I/O
I
HTS
I
HTS
29
R4
2
/S0
I/O
I
STH
O
STH
30
R4
3
/PWM I/O
I
SDISP
I
DISP SELECT : NU
31
R7
0
/BUZZ I/O
I
BUZZ
O
BUZZER : NU
32
R7
1/
SCK2 I/O
I
DSCK
O
DOT DISP CONT. SCK : NU
33
R7
2
/SI2
I/O
I
SRES
O
SYSTEM RESET : NU
PULL-DOWN
34
R7
3
/S02
I/O
O
DS0
O
DOT DISP CONT. SO : NU
35
R8
0
I/O
O
SHEN
O
SHEN
36
R8
1
I/O
O
IRQ
O
IRQ : NU
37
R9
0
I
I
KR0
I
KEY RETURN 0 : NU
38
R9
1
I
I
KR1
I
KEY RETURN 1 : NU
39
R9
2
I
I
KR2
I
KEY RETURN 2 : NU
40
R9
3
I
I
KR3
I
KEY RETURN 3 : NU
41
RESET
CKDC IV RESET
42
OSC2
4.91 MHz
43
OSC1
4.91MHz
44
GND
GND
45
CL1
32.768 KHz : NU
46
CL2
32.768 KHz : NU
47
TEST
I
I
+5V
5V
48
D0
I/O
H-Z
G0
O
7 SEG DIG 0
PULL-DOWN
49
D1
I/O
H-Z
G1
O
7 SEG DIG 1
PULL-DOWN
50
D2
I/O
H-Z
G2
O
7 SEG DIG 2
PULL-DOWN
51
D3
I/O
H-Z
G3
I
7 SEG DIG 3
PULL-DOWN
52
D4
I/O
H-Z
G4
O
7 SEG DIG 4
PULL-DOWN
53
D5
I/O
H-Z
G5
O
7 SEG DIG 5
PULL-DOWN
54
D6
I/O
H-Z
G6
O
7 SEG DIG 6
PULL-DOWN
55
D7
I/O
H-Z
G7
O
7 SEG DIG 7 : NU
PULL-DOWN
56
D8
I/O
H-Z
G8
O
7 SEG DIG 8 : NU
PULL-DOWN
57
D9
I/O
H-Z
G9
O
7 SEG DIG 9 : NU
PULL-DOWN
58
D10
I/O
H-Z
G10
O
7 SEG DIG 10 : NU
PULL-DOWN
59
D11
I/O
H-Z
G11
O
7 SEG DIG 11 : NU
60
D12
I/O
H-Z
PO0
O
: NU
61
D13
I/O
H-Z
PO10
O
: NU
62
D14
I/O
H-Z
PO2
O
: NU
63
D15
I/O
H-Z
PO3
O
: NU
64
R0
0
I/O
H-Z
SA
O
DB4 : SEG-A
PULL-DOWN
NOTE 3: Pull-up/down in the table indicates that the lines concerned
require external pull-up/down resistance.
VCC
VCC
R41
6.2k
6.2k
R44
4.3k
4.3k
7
6
1
3
12
IC4A
BA10339
BA10339
R54
1.5k
1.5k
R48
1W/0.33
1W/0.33
1
4
T1
Q1
2SC3144
2SC3144
A
B
About
0.6V
– 2 –
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