Samsung S3F84B8 - Manual (Page 20)

S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00 2 HARDWARE IMPLEMENTATION
2-14
2.6.3 KEY AND DISPLAY CIRCUIT
Figure 2-9 shows the circuit diagram for key and display.
SEG
8/
KS8
SEG4/
KS4
SEG5/
KS5
GR
ID
4
GRID3
SEG1/
KS1
SEG2/
KS2
SEG3/
KS3
GRID7
GRID6
GRID5
5V
GND
GRID4
SEG8/KS8
K4 KEY K2 KEY
K3
KEY
K1
KEY
K5
KEY
K6
KEY
K7
KEY
K8
KEY
KEY 1
KEY 2
2
1
R9
constant
2
1
R7
constant
2
1
R10
constant
2
1
R11
constant
2
1
R12
constant
2
1
R14
constant
GND
GRID2
GRID1
SEG
3
/KS
3
SEG
1
/KS
1
1 2
D1
LED
SEG
4
/KS
4
1 2
D2
LED
SEG
5
/KS
5
1 2
D3
LED
1 2
D4
LED
SEG
6
/KS
6
SEG
8
/KS
8
SEG1/KS1
SEG4/KS4
2
1
R18 constant
SEG3/KS3
2
1
R17
constant
GRID7
0
0
2 1 R6
constant
5V
2
1
R8
constant
+ C26
PF
1
2
C27
PF
GND
2
1
R29
constant
2
1
R32
constant
0
5V
KEY 1
KEY 2
SEG1/KS1
5V
NC
1
DIO
2
CLK
3
STB
4
KEY 1
5
KEY 2
6
VDD0
7
SEG1/KS1
8
SEG2/KS2
9
SEG3/KS3
10
SEG4/KS4
11
SEG5/KS5
12
SEG6/KS6
13
SEG7/KS7
14
GND0
28
GRID1
27
GRID2
26
GND
25
GRID3
24
GRID4
23
GND1
22
VDD1
21
SEG14/GRID5
20
SEG13/GRID6
19
SEG12/GRID7
18
SEG10
17
SEG9
16
SEG8/KS8
15
U2
TM1628
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
12
D8
4LED
SEG4/KS4
SEG3/KS3
SEG2/KS2
GR
ID
1
SEG5/KS5
SEG
6/
KS6
SEG
7/
KS7
GR
ID
2
SEG7/KS7
SEG6/KS6
GR
ID
3
Figure 2-9 Key and Display Circuit
There are eight keys for power on, power grade selection, and some LEDs to display the operating status and
power grade. TM1628 controls the key and display circuit. MCU communicates with TM1628 through three I/Os:
DIO for data transfer, CLK as serial clock, and STB for chip enable.