HOLTEK HT45R2K-B

Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
HT45R2K-C
HT45R2K-B
HT45R2K-A
Revision: 1.20
Date: ��
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Table of Contents
Features.......................................................................................................................... 5
General Description ...................................................................................................... 6
Selection Table............................................................................................................... 6
Block Diagram................................................................................................................ 6
Pin Assignment.............................................................................................................. 7
Pin Description............................................................................................................... 7
Absolute Maximum Ratings........................................................................................ 10
D.C. Characteristics..................................................................................................... 10
A.C. Characteristics..................................................................................................... 12
Operational Amplifier Electrical Characteristics....................................................... 13
Instrumentation Amplifier Electrical Characteristics................................................ 13
Power-on Reset Characteristics................................................................................. 13
System Architecture..................................................................................................... 14
Clocking and Pipelining........................................................................................................... 14
Program Counter – PC ........................................................................................................... 15
Stack....................................................................................................................................... 16
Arithmetic and Logic Unit – ALU............................................................................................. 16
Program Memory.......................................................................................................... 17
Structure.................................................................................................................................. 17
Special Vectors....................................................................................................................... 17
Look-up Table.......................................................................................................................... 18
Table Program Example.......................................................................................................... 19
Data Memory................................................................................................................. 20
Structure.................................................................................................................................. 20
Special Purpose Data Memory............................................................................................... 22
Special Function Registers......................................................................................... 22
Indirect Addressing Registers – IAR0, IAR1........................................................................... 22
Memory Pointers – MP0, MP1................................................................................................ 22
Accumulator – ACC................................................................................................................. 23
Program Counter Low Register – PCL.................................................................................... 23
Bank Pointer – BP................................................................................................................... 24
Status Register – STATUS...................................................................................................... 24
System Control Registers – CTRL0, CTRL1........................................................................... 25
Rev. 1.20
2
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Oscillator Configuration.............................................................................................. 27
External Crystal/Ceramic Oscillator – HXT............................................................................. 28
External RC Oscillator – ERC................................................................................................. 28
Internal RC Oscillator – HIRC................................................................................................. 29
External 32.768kHz Crystal Oscillator – LXT.......................................................................... 29
LXT Oscillator Low Power Function........................................................................................ 30
Internal 12kHz Oscillator – LIRC............................................................................................. 30
Watchdog Timer – WDT............................................................................................... 30
Watchdog Timer Clock Source................................................................................................ 30
Watchdog Timer Operation..................................................................................................... 30
Operating Modes.......................................................................................................... 34
Power Down Mode.................................................................................................................. 34
Reset and Initialisation................................................................................................ 36
Reset Functions...................................................................................................................... 36
Reset Initial Conditions........................................................................................................... 38
Input/Output Ports........................................................................................................ 41
Pull-high Resistors.................................................................................................................. 41
Port A Wake-up ...................................................................................................................... 42
I/O Port Control Registers....................................................................................................... 42
Pin-shared Functions.............................................................................................................. 43
I/O Pin Structures.................................................................................................................... 44
Programming Considerations.................................................................................................. 45
Timer/Event Counters.................................................................................................. 45
Timer Mode............................................................................................................................. 50
Event Counter Mode............................................................................................................... 50
Pulse Width Measurement Mode............................................................................................ 51
Prescaler................................................................................................................................. 52
Buzzer..................................................................................................................................... 52
I/O Interfacing.......................................................................................................................... 54
Programming Considerations.................................................................................................. 54
Timer Program Example......................................................................................................... 55
Vibration Sensor Amplifier.......................................................................................... 56
Touch Key Module........................................................................................................ 56
Touch Key Structure................................................................................................................ 56
Touch Key Register Definition................................................................................................. 56
Touch Key Operation............................................................................................................... 62
Touch Key Interrupts............................................................................................................... 63
Programming Considerations.................................................................................................. 63
Charge Pump and Voltage Regulator......................................................................... 63
Operation................................................................................................................................ 63
Dual Slope A/D Converter ........................................................................................... 65
Dual Slope Anolog Digital Convertor Operation...................................................................... 67
Rev. 1.20
3
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Interrupts....................................................................................................................... 70
Interrupt Register.................................................................................................................... 70
Interrupt Operation.................................................................................................................. 72
Interrupt Priority....................................................................................................................... 74
External Interrupt..................................................................................................................... 74
Timer/Event Counter Interrupt................................................................................................. 75
Multi-function Interrupt............................................................................................................ 75
A/D Converter Interrupt........................................................................................................... 76
Touch Key Interrupt................................................................................................................. 76
Programming Considerations.................................................................................................. 76
LCD Driver..................................................................................................................... 77
LCD Memory........................................................................................................................... 77
LCD Registers......................................................................................................................... 78
LCD Clock............................................................................................................................... 79
LCD Driver Output................................................................................................................... 79
LCD Voltage Source and Biasing............................................................................................ 80
Programming Considerations.................................................................................................. 81
Configuration Options............................................................................................................. 82
Body Fat Measurement Function................................................................................ 83
Sine Wave Generator.............................................................................................................. 83
Amplifier.................................................................................................................................. 85
Filter........................................................................................................................................ 87
Application Circuits..................................................................................................... 88
Instruction Set.............................................................................................................. 89
Introduction............................................................................................................................. 89
Instruction Timing.................................................................................................................... 89
Moving and Transferring Data................................................................................................. 89
Arithmetic Operations.............................................................................................................. 89
Logical and Rotate Operations................................................................................................ 89
Branches and Control Transfer............................................................................................... 90
Bit Operations......................................................................................................................... 90
Table Read Operations........................................................................................................... 90
Other Operations..................................................................................................................... 90
Instruction Set Summary............................................................................................. 91
Table conventions................................................................................................................... 91
Instruction Definition................................................................................................... 93
Package Information.................................................................................................. 103
80-pin LQFP (10mm × 10mm) Outline Dimensions.............................................................. 104
Rev. 1.20
4
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Features
●● Operating Voltage:
–– fSYS= 4MHz: 2.2V~5.5V
–– fSYS= 8MHz: 3.3V~5.5V
●● Oscillator types:
–– External Crystal -- HXT
–– External Low Speed Crystal -- LXT
–– External RC -- ERC
–– Internal High Speed RC -- HIRC
–– Internal Low Speed RC -- LIRC
●● Up to 22 bidirectional I/O lines
●● One external interrupt input shared with an I/O lines
●● One 8-bit and two 16-bit programmable timer/event counters with overflow interrupt a 8-stage
prescaler
●● LCD driver with 24×8 segments
●● 16K×16 program memory
●● 256×8 data memory
●● Single differential input channel dual slope Analog to Digital Convertor with Operational
Amplifier
●● Watchdog Timer with regulator power
●● Buzzer output
●● HALT and wake-up functions to reduce power consumption
●● Internal voltage regulator (3.3V) and charge pump
●● Internal reference voltage generator (1.5V)
●● 8-level subroutine nesting
●● Bit manipulation instruction
●● 16-bit table read instruction
●● Up to 0.5μs instruction cycle with 8MHz system clock at VDD= 5V
●● 63 powerful instructions
●● All instructions in 1 or 2 machine cycles
●● Low voltage reset function
●● One vibration sensor input
●● Four touch-key inputs
●● Body Fat circuit
●● 80-pin LQFP package
Rev. 1.20
5
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
General Description
The HT45R2K-C is an 8-bit high performance, RISC architecture microcontroller device, which
with its A/D Converter and LCD driver, can directly interface to analog signals and to LCD panels.
The device includes a range of other features such as low power consumption, I/O flexibility, timer
functions, oscillator options, dual slope A/D convertor, HALT and wake-up functions, watchdog
timer, vibration sensor etc. However as the device includes all the circuitry associated with body
fat measurement the device is especially suitable for this specific application area, being able to
significantly reduce the need for the usual external components.
Selection Table
Part No.
HT45R2K-A
Program Memory
4K × 16
HT45R2K-B
8K × 16
HT45R2K-C
16K × 16
Block Diagram

Rev. 1.20

6
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Pin Assignment
DSRR
62
61
69
63
70
DSRC
RF2
71
DSCC
RF1
72
64
FIL
73
65
FVL
74
RFC
SIN
75
CP0N
C2
76
66
C1
77
TO
VC
78
68
VAB
67
COM0
80
79
FIR
COM1
FVR
COM2
COM3
1
60
DCHOP
COM4/SEG27
2
59
DOPAO
COM5/SEG26
3
58
DOPAN
COM6/SEG25
4
57
DOPAP
COM7/SEG24
5
56
OP5N
SEG23
6
55
OP5P
SEG22
7
54
AVSS
SEG21
8
53
VOREG
SEG20
9
52
VOCHP
SEG19
10
51
CHPC1
SEG18
11
50
CHPC2
SEG17
12
49
VOBGP
SEG16
13
48
TH/LB
SEG15
14
47
AVDD
SEG14
15
46
PB5/TMR0
SEG13
16
45
PB4/INT
SEG12
17
44
PB3/TK4
SEG11
18
43
PB2/TK3
SEG10
19
42
PB1/TK2
SEG9
20
41
PB0/TK1
HT45R2K-C
80 LQFP-A
VSS
PA5/OSC2
40
PA4/XT1
PA6/OSC1
37
PA3/XT2
VDD
36
PA2/BZB
39
35
PA1/BZ
38
33
PA0/VIB
34
32
PC2/SEG2
PA7/RESB
PC3/SEG3
NC
27
31
26
PC4/SEG4
PC0/TMR1/SEG0
25
PC6/SEG6
PC5/SEG5
30
24
PC7/SEG7
29
23
SEG8
PC1/TMR2/SEG1
22
28
21
Pin Description
Pin Name
PA0/VIB
PA1/BZ
PA2/BZB
PA3/XT2
PA4/XT1
Rev. 1.20
Function
OPT
I/T
O/T
Description
PA0
PAPU
PAWK
ST
VIB
VIBRC
—
PA1
PAPU
PAWK
ST
CMOS General purpose I/O. Register enabled pull-up and wake-up.
BZ
SFS
—
CMOS Buzzer output
PA2
PAPU
PAWK
ST
CMOS General purpose I/O. Register enabled pull-up and wake-up
BZB
SFS
—
CMOS Complementary buzzer output
PA3
PAPU
PAWK
ST
CMOS General purpose I/O. Register enabled pull-up and wake-up.
XT2
CO
—
PA4
PAPU
PAWK
ST
XT1
CO
LXT
CMOS General purpose I/O. Register enabled pull-up and wake-up.
—
LXT
Vibration input
LXT pin
CMOS General purpose I/O. Register enabled pull-up and wake-up.
—
LXT pin
7
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Pin Name
PA5/OSC2
PA6/OSC1
PA7/RES
PB0/TK1
PB1/TK2
PB2/TK3
PB3/TK4
PB4/INT
PB5/TMR0
Function
OPT
I/T
PA5
PAPU
PAWK
ST
OSC2
CO
—
PA6
PAPU
PAWK
ST
OSC1
CO
HXT
PA7
PAWK
ST
RES
CO
ST
PB0
PBPU
ST
TK1
TKM0C1
—
PB1
PBPU
ST
TK2
TKM0C1
—
PB2
PBPU
ST
TK3
TKM0C1
—
PB3
PBPU
ST
TK4
TKM0C1
—
PB4
PBPU
ST
INT
CTRL1
INTC0
ST
PB5
PBPU
ST
TMR0
TMR0C
ST
PC0
PCPU
ST
O/T
Description
CMOS General purpose I/O. Register enabled pull-up and wake-up.
HXT
HXT pin
CMOS General purpose I/O. Register enabled pull-up and wake-up.
—
HXT/ERC pin
NMOS General purpose I/O. Register enabled wake-up.
—
Reset input
CMOS General purpose I/O. Register enabled pull-up.
—
Touch key 1 input
CMOS General purpose I/O. Register enabled pull-up.
—
Touch key 2 input
CMOS General purpose I/O. Register enabled pull-up.
—
Touch key 3 input
CMOS General purpose I/O. Register enabled pull-up.
—
Touch key 4 input
CMOS General purpose I/O. Register enabled pull-up.
—
External interrupt input
CMOS General purpose I/O. Register enabled pull-up.
—
External Timer 0 clock input
CMOS General purpose I/O. Register enabled pull-up.
PC0/TMR1/
SEG0
TMR1
TMR1C
ST
SEG0
LCDOUT
—
CMOS LCD segment output
PC1/TMR2/
SEG1
PC1
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
TMR2
TMR2C
ST
SEG1
LCDOUT
—
CMOS LCD segment output
PC2
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
SEG2
LCDOUT
—
CMOS LCD segment output
PC3
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
SEG3
LCDOUT
—
CMOS LCD segment output
PC4
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
SEG4
LCDOUT
—
CMOS LCD segment output
PC5
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
SEG5
LCDOUT
—
CMOS LCD segment output
PC6
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
SEG6
LCDOUT
—
CMOS LCD segment output
PC2/SEG2
PC3/SEG3
PC4/SEG4
PC5/SEG5
PC6/SEG6
—
—
External Timer 1 clock input
External Timer 2 clock input
PC7
PCPU
ST
CMOS General purpose I/O. Register enabled pull-up.
SEG7
LCDOUT
—
CMOS LCD segment output
SEG8~SEG23
SEGn
—
—
CMOS LCD segment outputs
COM0~COM3
COMn
—
—
CMOS LCD common outputs
LCDC
—
CMOS
PC7/SEG7
COM4/SEG27
Rev. 1.20
COM4
SEG27
LCD common output
LCD segment output
8
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Pin Name
COM5/SEG26
COM6/SEG25
COM7/SEG24
Function
COM5
SEG26
COM6
SEG25
COM7
SEG24
OPT
I/T
O/T
LCDC
—
CMOS
LCDC
—
CMOS
LCDC
—
CMOS
Description
LCD common output
LCD segment output
LCD common output
LCD segment output
LCD common output
LCD segment output
VAB
VAB
—
—
NS
LCD voltage pump
VC
VC
—
—
NS
LCD voltage pump
C1
C1
—
—
NS
LCD voltage pump
C2
C2
—
—
NS
LCD voltage pump
VOBGP
VOBGP
—
—
—
Band gap voltage output pin (for internal use)
VOREG
VOREG
—
—
PWR Regulator output 3.3V
VOCHP
VOCHP
—
—
PWR Charge pump output
CHPC1
CHPC1
—
—
NS
Charge pump capacitor – Positive
CHPC2
CHPC2
—
—
NS
Charge pump capacitor – Negative
DOPAN
DOPAN
—
NS
—
OPA Negative input
DOPAP
DOPAP
—
NS
—
OPA Positive input
DOPAO
DOPAO
—
—
NS
OPA output
DCHOP
DCHOP
—
—
NS
OPA Chopper pin
TH
—
NS
—
Temperature sensor input
LB
—
NS
—
Low battery voltage input
DSRR
DSRR
—
NS
—
Reference signal input
DSRC
DSRC
—
NS
—
Integrator negative input
DSCC
TH/LB
DSCC
—
NS
—
Comparator negative input
SIN
SIN
—
—
NS
Sine wave output
FVR
FVR
—
NS
—
Foot resistor channel
FVL
FVL
—
NS
—
Foot resistor channel
FIL
FIL
NS
—
—
Foot resistor channel
FIR
FIR
—
NS
—
Foot resistor channel
RF1
RF1
—
—
NS
Reference impedance channel
RF2
RF2
—
—
NS
Reference impedance channel
RFC
RFC
—
—
—
ADC analog input
T0
—
—
—
OPAC output
CP0N
CP0N
—
NS
—
The inverting input of CP0
OP5N
OP5N
—
NS
—
The inverting input of OP5
OP5P
OP5P
—
NS
—
The non-inverting input of OP5
VDD
VDD
—
PWR
—
Power supply
VSS
VSS
—
PWR
—
Ground
AVDD
AVDD
—
PWR
—
Analog power supply
AVSS
AVSS
—
PWR
—
Analog ground
T0
Note: I/T: Input type; O/T: Output type
OPT: Optional by configuration option (CO) or register option
PWR: Power; CO: Configuration option
ST: Schmitt Trigger input; CMOS: CMOS output; NMOS: NMOS output
HXT: High frequency crystal oscillator
LXT: Low frequency crystal oscillator
NS: Non-standard input or output
Rev. 1.20
9
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Absolute Maximum Ratings
Supply Voltage ......................................................................................................VSS -0.3V to +6.0V
Input Voltage ..................................................................................................VSS -0.3V to VDD +0.3V
Storage Temperature .................................................................................................-50°C to +125°C
Operating Temperature ...............................................................................................-40°C to +85°C
IOL Total .................................................................................................................................. 150mA
IOH Total .................................................................................................................................-100mA
Total Power Dissipation ..................................................................................................... 500mW
Note: These are stress ratings only. Stresses exceeding the range specified under “Absolute Maximum
Ratings” may cause substantial damage to the device. Functional operation of this device at other
conditions beyond those listed in the specification is not implied and prolonged exposure to extreme
conditions may affect device reliability.
D.C. Characteristics
Symbol
Parameter
Operating Temperature: -40°C °C to 85°C Ta= 25°C Typical
Test Conditions
VDD
—
IDD1
Operating Current
(HXT, ERC,HIRC)
5V
IDD2
Operating Current
(HXT, ERC,HIRC)
3V
Operating Current
(HXT, ERC)
3V
Standby Current
ISTB2
Standby Current
ISTB3
Standby Current
(Internal RC 12kHz)
ISTB4
Standby Current
(Internal RC 12kHz)
ISTB5
Standby Current
ISTB6
Standby Current (LXT)
ISTB7
Standby Current
Rev. 1.20
2.2
—
5.5
V
3.3
—
5.5
V
0
—
VDD
V
—
4
8
mA
—
0.8
1.5
mA
—
2.5
4.0
mA
—
0.5
1.0
mA
—
1.5
3.0
mA
—
3
5
mA
No load, system HALT, ADC,
LCD and WDT off
—
—
1
μA
—
—
2
μA
No load, system HALT, ADC
and LCD off, WDT on
—
2.5
5.0
μA
—
8
15
μA
No load, system osc off, ADC
and WDT off
—
2
5
μA
—
6
10
μA
—
380
500
μA
—
—
5
μA
—
—
15
μA
—
390
510
μA
—
2
4
—
8
16
fSYS= 8MHz
LCD Highest Voltage
ISTB1
Unit
—
VLCD
Operating Current
(HXT, ERC,HIRC)
Max.
fSYS= 4MHz
Operating Voltage
IDD4
Typ.
—
VDD
IDD3
Min.
Conditions
5V
5V
5V
3V
5V
3V
5V
3V
5V
5V
3V
5V
5V
3V
5V
—
No load, fSYS= 8MHz ADC off
No load, fSYS= 4MHz ADC off
No load, fSYS= 2MHz ADC off
VOREG= 3.3V, fSYS= 4MHz ADC
on, ADC clock is 125kHz (all
other analog devices off)
No load, system osc off, ADC and
WDT off LCD ON(1/3 R type)
No load, system HALT, LXT osc
slowly start-up, WDTOSC off,
LXT on
No load, system osc off, ADC and
WDT off, LCD on (1/3 R type),
(LCD Bias current= 50μA)
No load, Only vibration sensor
turn on&VIB pin connected a
0.1μF cap to VSS, WDT off
10
μA
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Symbol
Parameter
Test Conditions
VDD
Conditions
Min.
Typ.
Max.
Unit
VIL1
Input Low Voltage for I/O
Ports, TMR0, TMR1, TMR2
and INT
5V
—
0.0
—
1.5
V
—
—
0.0
—
0.2VDD
V
VIH1
Input High Voltage for I/O
Ports, TMR0, TMR1, TMR2
and INT
5V
—
3.5
—
5.0
V
—
—
0.8VDD
—
1.0VDD
V
VIL2
Input Low Voltage (RES)
—
—
0
—
0.4VDD
V
VIH2
Input High Voltage (RES)
—
—
VLVR1
VLVR2
VLVR3
Low Voltage Reset
—
VLVR4
IOL1
IOH1
I/O Port Sink Current
I/O Port Source Current
3V
5V
3V
5V
IOL2
LCD Common and Segment
Sink Current
3V
IOH2
LCD Common and Segment
Source Current
3V
IOL3
PA7 Sink Current
RPH
VVIBWK
Pull-high Resistance of I/O Ports
Minimum Voltage to Wake
MCU by the Vibration
Sensor Input
5V
5V
5
0.9VDD
—
VDD
V
Configuration Option: 2.1V
2.0
2.1
2.2
V
Configuration Option: 2.55V
2.40
2.25
2.70
V
Configuration Option: 3.15V
3.00
3.15
3.30
V
Configuration Option: 3.8V
3.6
3.8
4.0
V
4
8
—
mA
10
20
—
mA
-2
-4
—
mA
VOL= 0.1VDD
VOH= 0.9VDD
VOL= 0.1VDD
VOH= 0.9VDD
VOL= 0.1VDD
-5
-10
—
mA
210
420
—
μA
350
700
—
μA
-80
-160
—
μA
-180
-360
—
μA
2
3
—
mA
3V
—
20
60
100
KΩ
5V
—
10
30
50
KΩ
100Hz~1kHz sine wave (Note)
250
—
—
mV
—
Charge Pump on
2.2
—
3.6
V
—
Charge Pump off
3.7
—
5.5
V
—
No load
3.0
3.3
3.6
V
—
VDD = 3.7V~5.5V Charge Pump
off Current<= 10mA
—
100
—
mV
—
VDD = 2.4V~3.6V Charge Pump
on Current <= 6mA
—
100
—
mV
2.4V
3V
5V
Charge Pump and Regulator
VCHP
Input Voltage
VOREG
Output Voltage
VREGDP1
VREGDP2
Regulator Output Voltage Drop
(Compared with No Load)
Dual Slope AD Convertor, Amplifier and Band Gap
VADOFF
Input Offset Range
—
VOREG= 3.3V
—
500
800
μV
VRFGTC
Reference Generator
Temperature Coefficient
—
VOREG= 3.3V
—
50
—
ppm/C
VICMR
Common Mode Input Range
—
Amplifier, No load
0.2
—
VOREG-1.2
V
—
Integrator, No load
1.2
—
VOREG-0.2
V
Note: Test Circuit for VVMBWK.
Rev. 1.20
11
May 30, 2013
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A.C. Characteristics
Symbol
Parameter
System Clock (RC)
fSYS
System Clock (HXT )
Operating Temperature: -40°C to 85°C Ta= 25°C Typical
Test Conditions
VDD
Conditions
2.2V~5.5V
—
HIRC OSC
fERC
ERC OSC
fTIMER
Timer I/P Frequency
(TMR0,TMR1,TMR2)
tWDTOSC
Watchdog Oscillator Period
tRES
Typ.
Max.
Unit
400
—
4000
kHz
2.2V~5.5V
—
400
—
4000
kHz
3.3V~5.5V
—
400
—
8000
kHz
4.5V~5.5V
fHIRC
Min.
400
—
12000
kHz
3V/5V
Ta= 25°C
—
-2%
4
+2%
MHz
3V/5V
Ta= 25°C
-2%
8
+2%
MHz
5V
Ta= 25°C
-2%
12
+2%
MHz
3V/5V
Ta= 0~70°C
-5%
4
+5%
MHz
3V/5V
Ta= 0~70°C
-5%
8
+5%
MHz
5V
Ta= 0~70°C
-5%
12
+5%
MHz
2.2V~3.6V Ta= 0~70°C
-8%
4
+8%
MHz
3.0V~5.5V Ta= 0~70°C
-8%
4
+8%
MHz
3.0V~5.5V Ta= 0~70°C
-8%
8
+8%
MHz
4.5V~5.5V Ta= 0~70°C
-8%
12
+8%
MHz
2.2V~3.6V Ta= -40~85°C
-12%
4
+12%
MHz
3.0V~5.5V Ta= -40~85°C
-12%
4
+12%
MHz
3.0V~5.5V Ta= -40~85°C
-12%
8
+12%
MHz
4.5V~5.5V Ta= -40~85°C
-12%
12
+12%
MHz
5V
Ta= 25°C, R= 120K
-2%
4
+2%
MHz
5V
Ta= 0~70°C, R= 120K
-5%
4
+5%
MHz
5V
Ta= -40~85°C, R= 120K
-7%
4
+7%
MHz
2.2V~5.5V Ta= -40~85°C, R= 120K
-11%
4
+11%
MHz
2.2V~5.5V
—
0
—
4000
kHz
3V
—
45
90
180
μs
5V
—
32
65
130
μs
External Reset Low Pulse Width
—
—
1
—
—
μs
tSST
System Start-up Timer Period
(Wake-up from HALT)
—
—
2
1024
—
tSYS
tINT
Interrupt Pulse Width
—
—
1
—
—
μs
tLVR
Low Voltage Width to Reset
—
—
0.25
1.00
2.00
ms
Note: 1. tSYS = 1/fSYS
2. To maintain the accuracy of the internal HIRC oscillator frequency, a 0.1μF decoupling capacitor should
be connected between VDD and VSS and located as close to the device as possible.
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Operational Amplifier Electrical Characteristics
Symbol
Parameter
Test Conditions
VDD
Conditions
—
Min.
Typ.
Max.
Unit
2.2
—
5.5
V
μA
DC Electrical Characteristics
VDD
Supply Voltage
—
ICC
Supply Current Per
Signal Amplifier
5V
No load
150
360
500
SR
Slew Rate at Unity Gain
3V
RL= 100KΩ, CL= 100pF
7.5
—
—
V/μs
GBW
Gain Bandwidth Product
3V
RL= 100KΩ, CL= 100pF
—
—
2
MHz
SR
Slew Rate at Unity Gain
3V
RL= 100KΩ, CL= 100pF
7.5
—
—
V/μs
GBW
Gain Bandwidth Product
3V
RL= 100KΩ, CL= 100pF
—
—
5
MHz
Typ.
Max.
Unit
OP0, OP2
OP1
Instrumentation Amplifier Electrical Characteristics
Symbol
Parameter
Test Conditions
VDD
Condition
—
Min.
VDD
Supply Voltage
—
2.2
—
5.5
V
Icc
Supply Current
5V
Io= 0A
—
1.2
—
mA
SR
Slew Rate at Unity Gain
3V
RL= 100KΩ, CL= 100pF
7.5
—
—
V/µs
GBW
Gain Bandwidth Product
3V
RL= 100 KΩ, CL= 100pF
—
—
5
MHz
GER
Gain Error
—
—
-10%
—
10%
VOS
Input Offset Voltage
3V
—
-15
—
15
mV
Power-on Reset Characteristics
Symbol
Parameter
Test Conditions
VDD
Conditions
Min.
Typ.
Max.
Unit
VPOR
VDD Start Voltage to Ensure
Power-on Reset
—
—
—
—
100
mV
RRVDD
VDD Rising Rate to Ensure
Power-on Reset
—
—
0.035
—
—
V/ms
VDCPOR_MAX
DC POR Maximum Voltage
—
—
0.6
—
2.2
V
tPOR1
Minimum Time for VDD
Stays at VPOR to Ensure
Power-on Reset
—
Without 0.1mF between
VDD and VSS
2
—
—
μs
tPOR2
Minimum Time for VDD
Stays at VPOR to Ensure
Power-on Reset
—
With 0.1mF between VDD
and VSS
10
—
—
μs
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
System Architecture
A key factor in the high-performance features of the Holtek range of microcontrollers is attributed
to the internal system architecture. The range of devices take advantage of the usual features found
within RISC microcontrollers providing increased speed of operation and enhanced performance.
The pipelining scheme is implemented in such a way that instruction fetching and instruction
execution are overlapped, hence instructions are effectively executed in one cycle, with the
exception of branch or call instructions. An 8-bit wide ALU is used in practically all operations
of the instruction set. It carries out arithmetic operations, logic operations, rotation, increment,
decrement, branch decisions, etc. The internal data path is simplified by moving data through the
Accumulator and the ALU. Certain internal registers are implemented in the Data Memory and
can be directly or indirectly addressed. The simple addressing methods of these registers along
with additional architectural features ensure that a minimum of external components is required to
provide a functional I/O and A/D control system with maximum reliability and flexibility.
Clocking and Pipelining
The system clock, derived from an RC oscillator is subdivided into four internally generated
non-overlapping clocks, T1~T4.The Program Counter is incremented at the beginning of the T1
clock during which time a new instruction is fetched. The remaining T2~T4 clocks carry out the
decoding and execution functions. In this way, one T1~T4 clock cycle forms one instruction cycle.
Although the fetching and execution of instructions takes place in consecutive instruction cycles, the
pipelining structure of the microcontroller ensures that instructions are effectively executed in one
instruction cycle. The exception to this are instructions where the contents of the Program Counter
are changed, such as subroutine calls or jumps, in which case the instruction will take one more
instruction cycle to execute.
For instructions involving branches, such as jump or call instructions, two instruction cycles are
required to complete instruction execution. An extra cycle is required as the program takes one
cycle to first obtain the actual jump or call address and then another cycle to actually execute the
branch. The requirement for this extra cycle should be taken into account by programmers in timing
sensitive applications.

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Program Counter – PC
During program execution, the Program Counter is used to keep track of the address of the
next instruction to be executed. It is automatically incremented by one each time an instruction
is executed except for instructions, such as “JMP” or “CALL” that demand a jump to a nonconsecutive Program Memory address. It must be noted that only the lower 8 bits, known as the
Program Counter Low Register, are directly addressable by user.
When executing instructions requiring jumps to non-consecutive addresses such as a jump
instruction, a subroutine call, interrupt or reset, etc. the microcontroller manages program control
by loading the required address into the Program Counter. For conditional skip instructions, once
the condition has been met, the next instruction, which has already been fetched during the present
instruction execution, is discarded and a dummy cycle takes its place while the correct instruction is
obtained.
Program Counter
Program Counter High Byte
PCL Register Low Byte
PC13~PC8
PCL7~PCL0
The lower byte of the Program Counter, known as the Program Counter Low register or PCL, is
available for program control and is a readable and writeable register. By transferring data directly
into this register, a short program jump can be executed directly, however, as only this low byte
is available for manipulation, the jumps are limited to the present page of memory, which is 256
locations. When such program jumps are executed it should also be noted that a dummy cycle will
be inserted.
The lower byte of the Program Counter is fully accessible under program control. Manipulating the
PCL might cause program branching, so an extra cycle is needed to pre-fetch. Further information
on the PCL register can be found in the Special Function Register section.
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Stack
This is a special part of the memory which is used to save the contents of the Program Counter
only. The stack is neither part of the data nor part of the program space, and is neither readable nor
writeable. The activated level is indexed by the Stack Pointer, and is neither readable nor writeable.
At a subroutine call or interrupt acknowledge signal, the contents of the Program Counter are pushed
onto the stack. At the end of a subroutine or an interrupt routine, signaled by a return instruction,
RET or RETI, the Program Counter is restored to its previous value from the stack. After a device
reset, the Stack Pointer will point to the top of the stack.
P ro g ra m
T o p o f S ta c k
B o tto m
S ta c k L e v e l 1
S ta c k L e v e l 2
S ta c k
P o in te r
S ta c k L e v e l 3
o f S ta c k
C o u n te r
P ro g ra m
M a m o ry
S ta c k L e v e l 8
If the stack is full and an enabled interrupt takes place, the interrupt request flag will be recorded
but acknowledge signal will be inhibited. When the Stack Pointer is decremented, by RET or RETI,
the interrupt will be serviced. This feature prevents stack overflow allowing the programmer to use
the structure more easily. However, when the stack is full, a CALL subroutine instruction can still
be executed which will result in a stack overflow. Precautions should be taken to avoid such cases
which might cause unpredictable program branching.
Arithmetic and Logic Unit – ALU
The arithmetic-logic unit or ALU is a critical area of the microcontroller that carries out arithmetic
and logic operations of the instruction set. Connected to the main microcontroller data bus, the ALU
receives related instruction codes and performs the required arithmetic or logical operations after
which the result will be placed in the specified register. As these ALU calculation or operations may
result in carry, borrow or other status changes, the status register will be correspondingly updated to
reflect these changes. The ALU supports the following functions:
●● Arithmetic operations: ADD, ADDM, ADC, ADCM, SUB, SUBM, SBC, SBCM, DAA
●● Logic operations: AND, OR, XOR, ANDM, ORM, XORM, CPL, CPLA
●● Rotation RRA, RR, RRCA, RRC, RLA, RL, RLCA, RLC
●● Increment and Decrement INCA, INC, DECA, DEC
●● Branch decision, JMP, SZ, SZA, SNZ, SIZ, SDZ, SIZA, SDZA, CALL, RET, RETI
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Program Memory
The Program Memory is the location where the user code or program is stored. The device is
supplied with One-Time Programmable, OTP, memory where users can program their application
code into the device. By using the appropriate programming tools, OTP devices offer users the
flexibility to freely develop their applications which may be useful during debug or for products
requiring frequent upgrades or program changes.
Structure
The Program Memory has a capacity of 16K×16. The Program Memory is addressed by the Program
Counter and also contains data, table information and interrupt entries. Table data, which can be
setup in any location within the Program Memory, is addressed by separate table pointer registers.
The device has its Program Memory divided into two Banks, Bank 0 and Bank 1. The required Bank
is selected using Bit 5 of the BP Register.

Program Memory Structure
Special Vectors
Within the Program Memory, certain locations are reserved for special usage such as reset and
interrupts.
●● Reset Vector
This vector is reserved for use by the device reset for program initialization. After a device reset is
initiated, the program will jump to this location and begin execution.
●● External interrupt vector
This vector is used by the external interrupt. If the external interrupt pin on the device receives an
edge transition, the program will jump to this location and begin execution if the external interrupt is
enabled and the stack is not full. The external interrupt active edge transition type, whether high to
low, low to high or both is specified in the CTRL1 register.
●● Timer/Event 0/1 counter interrupt vector
This internal vector is used by the Timer/Event 0/1 Counters. If a Timer/Event Counter overflow
occurs, the program will jump to its respective location and begin execution if the associated Timer/
Event Counter interrupt is enabled and the stack is not full.
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●● Multi-function interrupt vector
This vector is used by the Multi-function interrupt. If the Timer/Event 2 Counter overflow or Touch
Key 16-bit or 10-bit Counter overflow, the program will jump to this location and begin execution if
the relevant interrupt is enabled and the stack is not full.
●● A/D Convertor interrupt vector
This internal vector is used by the A/D Convertor interrupt. If the A/D conversion process finishes,
the program will jump to this location and begin execution if the A/D Convertor interrupt is enabled
and the stack is not full.
●● Touch Key interrupt vector
This internal vector is used by the Touch Key interrupt. If the counter in the relevant Touch Key
module overflow occurs, the program will jump to this location and begin execution if the Touch
Key interrupt is enabled and the stack is not full.
Look-up Table
Any location within the Program Memory can be defined as a look-up table where programmers can
store fixed data. To use the look-up table, the table pointer must first be setup by placing the address
of the look up data to be retrieved in the table pointer register, TBLP. This register defines the total
address of the look-up table.
After setting up the table pointer, the table data can be retrieved from the Program Memory using
the “TABRDC[m]” or “TABRDL[m]” instructions, respectively. When the instruction is executed,
the lower order table byte from the Program Memory will be transferred to the user defined
Data Memory register [m] as specified in the instruction. The higher order table data byte from
the Program Memory will be transferred to the TBLH special register. Any unused bits in this
transferred higher order byte will be read as “0”.
The accompanying diagram illustrates the addressing data flow of the look-up table.
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Table Program Example
The following example shows how the table pointer and table data is defined and retrieved from the
microcontroller. This example uses raw table data located in the Program Memory which is stored there
using the ORG statement. The value at this ORG statement is “3F00H” which refers to the start address
of the last page within the 16K words Program Memory of the device. The table pointer is setup here to
have an initial value of “06H”. This will ensure that the first data read from the data table will be at the
Program Memory address “3F06H” or 6 locations after the start of the last page. Note that the value for
the table pointer is referenced to the first address of the present page if the “TABRDC [m]” instruction
is being used. The high byte of the table data which in this case is equal to zero will be transferred to the
TBLH register automatically when the “TABRDL [m]” instruction is executed.
Because the TBLH register is a read-only register and cannot be restored, care should be taken
to ensure its protection if both the main routine and Interrupt Service Routine use table read
instructions. If using the table read instructions, the Interrupt Service Routines may change the
value of the TBLH and subsequently cause errors if used again by the main routine. As a rule it is
recommended that simultaneous use of the table read instructions should be avoided. However, in
situations where simultaneous use cannot be avoided, the interrupts should be disabled prior to the
execution of any main routine table-read instructions. Note that all table related instructions require
two instruction cycles to complete their operation.
Instruction(s)
TABRDC [m]
TABRDL [m]
Table Location
b13
b12
b11
b10
b9
PC13 PC12 PC11 PC10 PC9
1
1
1
1
1
b8
b7
b6
b5
b4
b3
b2
b1
b0
PC8
@7
@6
@5
@4
@3
@2
@1
@0
1
@7
@6
@5
@4
@3
@2
@1
@0
Table Location
Note: 1. PC13~PC8: Current Program Counter bits
2. @7~@0: Table Pointer TBLP bits
3. b13~b0: Table address location bits
Table Read Program Example
tempreg1 db ?
;temporary register #1
tempreg2 db ?
;temporary register #2
:
:
mov a,06h ;initialise low table pointer - note that this ;address
mov tblp,a
;is referenced
:
:
tabrdl tempreg1
;transfers value in table referenced by table ;pointer data at program
;memory address “3F06H” transferred to tempreg1 ;and TBLH
dec tblp ;reduce value of table pointer by one tabrdl ;tempreg2
;transfers value in table referenced by table ;pointer data at program
;memory address “3F05H” transferred to tempreg2 ;and TBLH in this
;example the data “1AH” is transferred to tempreg1
;and data “0FH” to register tempreg2
:
:
org 3F00h
;sets initial address of program memory
dc 00Ah, 00Bh, 00Ch, 00Dh, 00Eh, 00Fh, 01Ah, 01Bh
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Data Memory
The Data Memory is a volatile area of 8-bit wide RAM internal memory and is the location where
temporary information is stored.
Structure
The data memory is divided into four banks, Bank0~3. The Bank0 is subdivided into two sections,
the first of these is an area of RAM, known as the Special Function Data Memory. Here are located
registers which are necessary for correct operation of the device. Many of these registers can be
read from and written to directly under program control, however, some remain protected from user
manipulation. The second area of Data Memory is reserved for general purpose use. All locations
within this area are read and write accessible under program control.
The general purpose data memory Bank1 and Bank2 are dedicated for the LCD and Sine Pattern
functions respectively while the Bank3 is used for general purpose data memory. The total capacity
of general purpose data memory, available for designer, is 256 bytes, composed by Bank0 and
Bank4. The accompanying table illustrates the Data Memory arrangement.
Capacity
256×8
Bank
Description
Bank 0(00H~3FH)
Special Function Data Memory( 64Bytes)
Bank 0(40H~FFH)
General Purpose Data Memory(192 Bytes)
Bank 1(40H~5BH)
General Purpose Data Memory for LCD(28 Bytes)
Bank 2(40H~7FH)
General Purpose Data Memory for Sine Pattern(64 Bytes)
Bank 3(40H~7FH)
General Purpose Data Memory(64 Bytes)
Note: The Data RAM Capacity consists of the general purpose data RAM in Bank0 and Bank3, except the Bank1
and Bank2 which are assigned to the LCD and Sine Pattern functions.
All microcontroller programs require an area of read/write memory where temporary data can be
stored and retrieved for use later. It is this area of RAM memory that is known as General Purpose
Data Memory. This area of Data Memory is fully accessible by the user program for both read and
write operations. By using the “SET [m].i” and “CLR [m].i” instructions individual bits can be set
or reset under program control giving the user a large range of flexibility for bit manipulation in the
Data Memory.
For this device, the Data Memory is divided into four banks, which are selected using a Bank
Pointer. Only data in Bank 0 can be directly addressed, data in Bank 1~3 must be indirectly
addressed.

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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Special Purpose Data Memory
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General Purpose Data Memory
Special Purpose Data Memory
This area of Data Memory is where registers, necessary for the correct operation of the
microcontroller, are stored. Most of the registers are both readable and writeable but some are
protected and are readable only, the details of which are located under the relevant Special Function
Register section. Note that for locations that are unused, any read instruction to these addresses will
return the value “00H”.
Special Function Registers
To ensure successful operation of the microcontroller, certain internal registers are implemented in
the Data Memory area. These registers ensure correct operation of internal functions such as timers,
interrupts, etc., as well as external functions such as I/O data control. The locations of these registers
within the Data Memory begin at the address “00H” and are mapped into from Bank 0 to Bank 3.
Any unused Data Memory locations between these special function registers and the point where the
General Purpose Memory begins is reserved and attempting to read data from these locations will
return a value of “00H”.
Indirect Addressing Registers – IAR0, IAR1
The Indirect Addressing Registers, IAR0 and IAR1, although having their locations in normal RAM
register space, do not actually physically exist as normal registers. The method of indirect addressing
for RAM data manipulation uses these Indirect Addressing Registers and Memory Pointers, in
contrast to direct memory addressing, where the actual memory address is specified. Actions on the
IAR0 and IAR1 registers will result in no actual read or write operation to these registers but rather
to the memory location specified by their corresponding Memory Pointers, MP0 or MP1. Acting as a
pair, IAR0 and MP0 can together access data from Bank 0 while the IAR1 and MP1 register pair can
access data from any bank. As the Indirect Addressing Registers are not physically implemented,
reading the Indirect Addressing Registers indirectly will return a result of “00H” and writing to the
registers indirectly will result in no operation.
Memory Pointers – MP0, MP1
Two Memory Pointers, known as MP0 and MP1 are provided. These Memory Pointers are physically
implemented in the Data Memory and can be manipulated in the same way as normal registers
providing a convenient way with which to indirectly address and track data. MP0 can only be used
to indirectly address data in Bank 0 while MP1 can be used to address data from Bank 0 to Bank 3.
When any operation to the relevant Indirect Addressing Registers is carried out, the actual address
that the microcontroller is directed to, is the address specified by the related Memory Pointer. Note
that indirect addressing using MP1 and IAR1 must be used to access any data in Bank 1~Bank 3.
The following example shows how to clear a section of four Data Memory locations already defined
as locations adres1 to adres4.
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Indirect Addressing Program Example
data .section ´data´
adres1
db ?
adres2
db ?
adres3
db ?
adres4
db ?
block
db ?
code .section at 0 ´code´
org00h
start：
mov a，04h
;setup size of block
mov block，a
mov a，offset adres1 ;Accumulator loaded with first RAM address
mov mp0，a
;setup memory pointer with first RAM address
loop：
clr IAR0
;clear the data at address defined by mp0
inc mp0
;increment memory pointer
sdz block
;check if last memory location has been cleared
jmp loop
continue：
The important point to note here is that in the example, no reference is made to specific Data
Memory addresses.
Accumulator – ACC
The Accumulator is central to the operation of any microcontroller and is closely related with
operations carried out by the ALU. The Accumulator is the place where all intermediate results
from the ALU are stored. Without the Accumulator it would be necessary to write the result of
each calculation or logical operation such as addition, subtraction, shift, etc., to the Data Memory
resulting in higher programming and timing overheads. Data transfer operations usually involve
the temporary storage function of the Accumulator; for example, when transferring data between
one user defined register and another, it is necessary to do this by passing the data through the
Accumulator as no direct transfer between two registers is permitted.
Program Counter Low Register – PCL
To provide additional program control functions, the low byte of the Program Counter is made
accessible to programmers by locating it within the Special Purpose area of the Data Memory. By
manipulating this register, direct jumps to other program locations are easily implemented. Loading
a value directly into this PCL register will cause a jump to the specified Program Memory location.
However, as the register is only 8-bit wide, only jumps within the current Program Memory page are
permitted. When such operations are used, note that a dummy cycle will be inserted.
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Bank Pointer – BP
In this device, the Program and Data Memory are divided into several banks. Selecting the required
Program and Data Memory area is achieved using the Bank Pointer. Bit 5 of the Bank Pointer is used
to select Program Memory Bank 0 or 1, while bits 0~1 are used to select Data Memory Banks 0~3.
The Data Memory is initialised to Bank 0 after a reset, except for the WDT time-out reset in the
Power Down Mode, in which case, the Data Memory bank remains unaffected. It should be noted
that Special Function Data Memory is not affected by the bank selection, which means that the
Special Function Registers can be accessed from within any bank. Directly addressing the Data
Memory will always result in Bank 0 being accessed irrespective of the value of the Bank Pointer.
Accessing data from banks other than Bank 0 must be implemented using indirect addressing.
As both the Program Memory and Data Memory share the same Bank Pointer Register, care must be
taken during programming.
BP Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
PMBP0
—
—
—
DMBP1
DMBP0
R/W
—
—
R/W
—
—
—
R/W
R/W
POR
—
—
0
—
—
—
0
0
Bit 7 ~ 6
Unimplemented, read as “0”
Bit 5
PMBP0: Program Memory Bank Pointer
0: Bank 0, Program Memory Address is from 0000H ~ 1FFFH
1: Bank 1, Program Memory Address is from 2000H ~ 3FFFH
Bit 4 ~ 2 Unimplemented, read as “0”
Bit 1 ~ 0
DMBP1 ~ DMBP0: Data Memory Bank Pointer
00: Bank 0 (for general purpose)
01: Bank 1 (for LCD)
10: Bank 2 (for sine generator)
11: Bank 3 (for general purpose)
Status Register – STATUS
This 8-bit register contains the zero flag(Z), carry flag (C), auxiliary carry flag(AC), overflow
flag(OV), power down flag(PDF), and watchdog time-out flag(TO). These arithmetic/logical
operation and system management flags are used to record the status and operation of the
microcontroller.
With the exception of the TO and PDF flags, bits in the status register can be altered by instructions
like any other register. Any data written into the status register will not change the TO and PDF
flags. In addition operations related to the status register may give different results from those
intended. The TO flag can be affected only by system power-up, a WDT time-out or executing the
“HALT” or “CLR WDT” instruction. The PDF flag can be affected only by executing the “HALT”
or “CLR WDT” instruction or a system power-up.
The Z, OV, C, AC flags generally reflect the statuses of the latest operations.
In addition, on entering the interrupt sequence or executing the subroutine call, the status
register will not be pushed onto stack automatically. If the contents of status are important
and the subroutine can corrupt the status register, the programmer has to take precautions
to save it properly.
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
STATUS Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
TO
PDF
OV
Z
AC
C
R/W
—
—
R
R
R/W
R/W
R/W
R/W
POR
—
—
0
0
x
x
x
x
"x" unknown
bit 7~6
bit 5
bit 4
bit 3
Unimplemented, read as "0"
TO: Watchdog Time-Out flag
0: After power up or executing the "CLR WDT" or "HALT" instruction
1: A watchdog time-out occurred.
PDF: Power down flag
0: After power up or executing the "CLR WDT" instruction
1: By executing the "HALT" instruction
OV: Overflow flag
0: no overflow
bit 1
1: an operation results in a carry into the highest-order bit but not a carry
out of the highest-order bit or vice versa.
Z: Zero flag
0: The result of an arithmetic or logical operation is not zero
1: The result of an arithmetic or logical operation is zero
AC: Auxiliary flag
bit 0
borrow from the high nibble into the low nibble in subtraction
C: Carry flag
bit 2
0: no auxiliary carry
1: an operation results in a carry out of the low nibbles in addition, or no
0: no carry-out
1: an operation results in a carry during an addition operation or if a borrow does not
take place during a subtraction operation
C is also affected by a rotate through carry instruction
System Control Registers – CTRL0, CTRL1
These registers are used to provide control over various internal functions. Some of these include
the Timer/Event Counter 2 internal source option, the LCD driver clock (fSUB) option, Power
down mode clock control, certain system clock options, external Interrupt edge trigger type, and the
32.768kHz crystal oscillator (LXT) enable control.
CTRL0 Register
Bit
7
6
5
4
3
2
1
0
Name
TCKS1
TCKS0
LFS
LCDCK1
LCDCK0
FSUBC
FSUBS
LXTLP
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
1
Bit 7~6
Rev. 1.20
TCKS1~TCKS0: Timer/Event Counter 2 internal source selection
00: fL (Low frequency clock)
01: fREF (Reference frequency clock generated from Touch Key module)
10: fSEN (Sensor frequency clock generated from Touch Key module)
11: fTMCK (Gated Sensor frequency clock generated from Touch Key module)
If the Touch Key module is disabled, the TCKS1 and TCKS0 bits are always set to “00”
and can not be written to.
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Bit 5
LFS: Low Frequency clock source fL selection
0: LIRC oscillator
1: LXT oscillator
Bit 4~3
LCDCK1~LCDCK0: To select the LCD driver clock
00: LCD clock = fSUB/3
01: LCD clock = fSUB/4
10: LCD clock = fSUB/8
11: LCD clock = fSUB/8
Bit2
FSUBC: fSUB Power down mode clock control
0: disabled
1: enabled
Bit1
FSUBS: fSUB Clock source selection
0: LIRC oscillator
1: LXT Oscillator
Bit0
LXTLP: LXT oscillator low power control function
0: LXT Oscillator quick start-up mode
1: LXT Oscillator Low Power Mode
CTRL1 Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
EINTC1
EINTC0
—
—
—
—
BZCS
LXTEN
R/W
R/W
R/W
—
—
—
—
R/W
R/W
POR
0
0
—
—
—
—
0
1
Bit 7~6
EINTC1, EINTC0: External interrupt edge selection
00: disable
01: falling edge trigger
10: rising edge trigger
11: dual edge trigger
Bit 5~2
Unimplemented, read as “0”
Bit 1
BZCS: Buzzer clock source selection
0: from Timer/Event Counter 0
1: from Timer/Event Counter 1
Bit 0
LXTEN: LXT oscillator control in Power down mode
0: disabled
1: enabled
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Oscillator Configuration
The device provides three system oscillator circuits known as a crystal oscillator (HXT), an external
RC oscillator (ERC) and an internal high speed RC oscillator (HIRC) which are used for the system
clock. There are also an internal 12kHz RC (LIRC) and a 32.768kHz crystal oscillator (LXT) which
can provide a source clock for the WDT clock named fS, the LCD driver clock, named fSUB and the
Timer/Event counters low frequency clock, named fL ,for various timing purposes.
High Frequency
Oscillation (HOSC)
“Halt”
Configuration Option
OSCON
HXT
f SYS
ERC
HIRC
Low Frequency
Oscillation (LOSC)
LXT
fL
Timer
f SYS/4
LIRC
f SYS
“Halt”
LFS
LCDCK [1:0]
FSUBC
f SUB
Prescaler
LCD
(/3, /4, /8)
FSUBS
f SYS /4
fs
WDT
Configuration Option
System Clock Configurations
In the Power down mode, the system oscillator, the internal 12kHz RC oscillator (LIRC) or the
external 32.768kHz crystal oscillator (LXT) may be enabled or disabled depending upon the
corresponding clock control bit described in the relevant sections. The system can be woken-up from
the Power down mode by the occurrence of an interrupt, a transition determined by configuration
options on any of the Port A pins, a WDT overflow or a timer overflow. The accompanying table
illustrates the Oscillator type list.
Type
Name
Freq.
Pins
HXT
400kHz~12MHz
OSC1/OSC2
External RC
ERC
400kHz~12MHz
OSC1
Internal High Speed RC
HIRC
4, 8 or 12MHz
—
External Low Speed Crystal
LXT
32.768kHz
XT1/XT2
Internal Low Speed RC
LIRC
12kHz
—
External Crystal
Oscillator Types
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
External Crystal/Ceramic Oscillator – HXT
The External Crystal/Ceramic System Oscillator is one of the system oscillator choices, which is
selected via configuration options. For most crystal oscillator configurations, the simple connection
of a crystal across OSC1 and OSC2 will create the necessary phase shift and feedback for
oscillation, without requiring external capacitors and resistors. However, if a resonator instead of
crystal is connected between OSC1 and OSC2, to ensure oscillation, it may be necessary to add two
small value capacitors, C1 and C2. Using a ceramic resonator will usually require two small value
capacitors, C1 and C2, to be connected for oscillation to occur. The values of C1 and C2 should be
selected in consultation with the crystal or resonator manufacturer’s specification.
External RC Oscillator – ERC
Using the ERC oscillator only requires that a resistor, with a value between 24kΩand
1.5MΩ, is connected between OSC1 and VDD, and a capacitor is connected between
OSC1 and ground, providing a low cost oscillator configuration. It is only the external
resistor that determines the oscillation frequency; the external capacitor has no influence
over the frequency and is connected for stability purposes only. Device trimming during the
manufacturing process and the inclusion of internal frequency compensation circuits are
used to ensure that the influence of the power supply voltage, temperature and process
variations
on the oscillation frequency are minimised. As a resistance/ frequency reference point, it
can be noted that with an external 120KΩ resistor connected and with a 5V voltage power
supply and temperature of 25 ℃ degrees, the oscillator will have a frequency of 4MHz
within a tolerance of 2%. Here only the OSC1 pin is used, which is shared with I/O pin PA6,
leaving pin PA5 free for use as a normal I/O pin
External RC Oscillator – ERC
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Internal RC Oscillator – HIRC
The internal RC oscillator is a fully integrated system oscillator requiring no external components.
The internal RC oscillator has three fixed frequencies of either 4MHz, 8MHz or 12MHz. Device
trimming during the manufacturing process and the inclusion of internal frequency compensation
circuits are used to ensure that the influence of the power supply voltage, temperature and process
variations on the oscillation frequency are minimised. As a result, at a power supply of either 3V or
5V and at a temperature of 25℃ degrees, the fixed oscillation frequency of 4MHz, 8MHz or 12MHz
will have a tolerance within 2%. Note that if this internal system clock option is selected, as it
requires no external pins for its operation, I/O pins PA5 and PA6 are free for use as normal I/O pins.
External 32.768kHz Crystal Oscillator – LXT
The External 32.768kHz Crystal Oscillator is one of the low frequency oscillator choices, which
is selected via a configuration option. This clock source has a fixed frequency of 32.768kHz and
requires a 32.768kHz crystal to be connected between pins XT1 and XT2. The external resistor and
capacitor components connected to the 32.768kHz crystal are necessary to provide oscillation. For
applications where precise frequencies are essential, these components may be required to provide
frequency compensation due to different crystal manufacturing tolerances. During power-up there is
a time delay associated with the LXT oscillator waiting for it to start-up.
When the microcontroller enters the Power down Mode, the system clock is switched off to stop
microcontroller activity and to conserve power. However, in many microcontroller applications it
may be necessary to keep the internal timers operational even when the microcontroller is in the
Power down Mode. To do this, another clock, independent of the system clock, must be provided.
The exact values of C1 and C2 should be selected in consultation with the crystal or resonator
manufacturer’s specification. The external parallel feedback resistor, Rp, is required.

H o lte k M C U
E x te r n a l 3 2 .7 6 8 k H z C r y s ta l O s c illa to r - L X T
LXT Oscillator C1 and C2 Values
Crystal Frequency
C1
C2
32768Hz
8pF
10pF
Note: 1. C1 and C2 values are for guidance only.
2. RP = 5M~10MΩ is recommended.
32768Hz Crystal Recommended
Capacitor Values
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
LXT Oscillator Low Power Function
The LXT oscillator can function in one of two modes, the Quick Start Mode and the Low Power
Mode. The mode selection is executed using the LXTLP bit in the CTRL0 register.
LXTLP Bit
LXT Mode
0
Quick Start
1
Low-power
After power on, the LXTLP bit will be automatically cleared to zero ensuring that the LXT oscillator
is in the Quick Start operating mode. In the Quick Start Mode the LXT oscillator will power up
and stabilise quickly. However, after the LXT oscillator has fully powered up it can be placed
into the Low-power mode by setting the LXTLP bit high. The oscillator will continue to run but
with reduced current consumption, as the higher current consumption is only required during the
LXT oscillator start-up. In power sensitive applications, such as battery applications, where power
consumption must be kept to a minimum, it is therefore recommended that the application program
sets the LXTLP bit high about 2 seconds after power-on.
It should be noted that, no matter what condition the LXTLP bit is set to, the LXT oscillator will
always function normally; the only difference is that it will take more time to start up if in the Lowpower mode.
Internal 12kHz Oscillator – LIRC
The Internal 12kHz RC Oscillator is one of the low frequency oscillator choices, which is selected via
configuration option. It is a fully integrated RC oscillator with a typical period of approximately 65us
at 5V, requiring no external components for its implementation. If the system enters the Power Down
Mode, the internal RC oscillator can still continue to run if its clock is necessary to be used to clock
the functions for timing purpose such as the WDT function, LCD Driver or Timer/Event Counters.
The internal RC oscillator can be disabled only when it is not used as the clock source for all the
peripheral functions determined by the configuration options of the WDT function and the relevant
control bits which determine the clock is enabled or disabled for related peripheral functions.
Watchdog Timer – WDT
The Watchdog Timer is provided to prevent program malfunctions or sequences from jumping to
unknown locations, due to certain uncontrollable external events such as electrical noise.
Watchdog Timer Clock Source
The WDT is implemented using an internal 12kHz RC oscillator known as LIRC, the external LXT
32.768kHz oscillator or the instruction clock which is the system clock divided by 4.
Watchdog Timer Operation
The timer is designed to prevent a software malfunction or sequence from jumping to an unknown
location with unpredictable results. A configuration option determines whether the Watchdog Timer
is to be always on or whether its enable/disable control is under software control. If the configuration
option chooses the always on option, then any WE4~WE0 values other than 01010 or 10101 will
result in an MCU reset being generated. If the configuration option chooses the software control
option then the Watchdog Timer can be disabled by setting the WE4~WE0 bits to a 10101 value.
A value of 01010 will enable the Watchdog Timer and any other value will generate an MCU reset.
The actual reset will be generated after 2~3 LIRC clock cycles.
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
WDT Config. Option
Always On
WE4 ~ WE0 bits
Enabled
10101
Enabled
Other values
Software Control
WDT Function
01010
MCU reset generated after 2~3 LIRC clock cycles
01010
Enabled
10101
Disabled
Other values
MCU reset generated after 2~3 LIRC clock cycles
WDT Functional Control Summary
The application can generate a software reset by writing a value other than 01010 and 10101 into the
WE4~WE0 bits. If this is done then the WRF flag in the WDTC1 register will be set.
The WDT clock is divided by an internal counter to give a ratio division with a range of 28~215
selected using the WS0~WS2 bits, to give a longer watchdog time-out period.
If the watchdog timer is disabled, the WDT timer will not generate a chip reset. So in the watchdog
timer disable mode, the WDT timer counter can be read out and can be cleared. This function is used
for the application program to access the WDT frequency to get the temperature coefficient for analog
component adjustment. The LIRC oscillator can be disabled or enabled by the oscillator enable control
bits LIRCEN1 and LIRCEN0 in the WDT control register WDTC for power saving reasons.
There are three registers related to the WDT function named WDTC, WDTC1 and WDTD. The
WDTC and WDTC1 registers control the WDT oscillator enable/disable and the WDT power
source. The WDTD register is the WDT counter content register and is read only.
The WDT power source selection bits named LIRCPWR1 and LIRCPWR0 are used to choose the
WDT power source. The WDT default power source is from VOCHP. The main purpose of the
regulator is to be used for WDT Temperature-coefficient adjustment. In this case, the application
program should enable the regulator before switching to the Regulator source. The LIRCEN1 and
LIRCEN0 bits can be used to enable or disable the LIRC oscillator. If the application does not use
the LIRC oscillator, then it needs to disable it in order to save power. When the LIRC oscillator is
disabled, then it is actually turned off, regardless of the setting of the relevant control bits which
select the LIRC oscillator as its clock source. When the LIRC oscillator is enabled, it can be used
as the clock source in the Power Down mode defined by the corresponding control bits of the
peripheral functions.
The WDT clock source may also come from the instruction clock, in which case the WDT will
operate in the same manner except that in the Power Down mode the WDT may stop counting and
lose its protecting purpose. If the device operates in a noisy environment, using the on-chip LIRC
oscillator is strongly recommended, since the HALT instruction will stop the system clock.
When the WDT overflows under normal operation a device reset will be executed and the status bit
“TO” will be set. In the Power down mode, the overflow executes a warm reset, here only the PC
and SP bits are reset to zero. There are three methods to clear the contents of the WDT, an external
reset - a low level on RES -, a software instruction or a HALT instruction.
There are two types of software instructions; the single “CLR WDT” instruction, or the pair of
instructions, “CLR WDT1” and “CLR WDT2”. Of these two types of instruction, only one type
of instruction can be active at a time depending on the configuration option – “CLR WDT” times
selection option. If the “CLR WDT” is selected (i.e., CLR WDT times equal one), any execution of
the “CLR WDT” instruction clears the WDT. If the “CLR WDT1 and CLR WDT2” option is chosen
(i.e., CLR WDT times equal two), these two instructions have to be executed to clear the WDT,
otherwise the WDT may reset the device due to a time-out.
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale

Watchdog Timer
WDTC Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
WS2
WS1
WS0
—
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
POR
1
1
1
—
s
s
0
1
LIRCEN1 LIRCEN0 LIRCPWR1 LIRCPWR0
Bit 7~5
WS2~WS0: WDT prescaler rate select
000: 28/fS
9
001: 2 /fS
10
010:
2
/fS
11
011:
2
/f
S
12
100: 2 /fS
101: 213/fS
14
110: 2 /fS
15
111: 2 /fS
Bit 4
unimplemented, read as "0"
Bit 3~2
LIRCEN1~ LIRCEN0: LIRC oscillator enable/disable control bits
00: LIRC oscillator is enabled
01: LIRC oscillator is disabled
10: LIRC oscillator is enabled
11: LIRC oscillator is enabled
It is strongly recommended to use “10” for WDT OSC enable
Bit 1~0
LIRCPWR1~ LIRCPWR0: LIRC Power Source Select
00: WDT power comes from VOCHP
01: WDT power comes from VOCHP
10: WDT power comes from Regulator
11: WDT power comes from VOCHP
It is strongly recommended to use “01” for VOCHP to prevent the noise to let the
WDT lose the power
The WDT clock (fS) is further divided by an internal counter to give longer watchdog
time-out period. In this device, the division ratio can be varied by selecting different
values of WS2~WS0 bits to give 28/fS to 215/fS division ratio range.
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
WDTC1 Register
Bit
7
6
5
4
3
2
1
0
Name
WE4
WE3
WE2
WE1
WE0
LVRF
LRF
WRF
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
1
0
1
0
x
0
0
Bit 7 ~ 3
WE4~WE0: WDT enable/disable/MCU reset control
01010B: enable – power on value
10101B: Function depends upon WDT configuration option.
For the WDT always on option this value will enable the WDT.
For the software control option this value will disable the WDT.
Other values: Generates MCU reset after 2~3 LIRC clock cycles.
Bit 2
LVRF: LVRF reset flag
0: LVR not active
1: LVR active
This bit can be cleared to “0” by the application program, but can not be set to “1”.
Bit 1
LRF: reset caused by LVRC setting
0: not active
1: active
This bit can be cleared to “0” by the application program, but can not be set to “1”.
Bit 0
WRF: reset generated by WE4~WE0 bits
WDTD Register
Bit
7
6
5
4
3
2
1
0
Name
WDTD7
WDTD6
WDTD5
WDTD4
WDTD3
WDTD2
WDTD1
WDTD0
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
Bit 7~0
Rev. 1.20
WDTD7~ WDTD0: WDT Counter value (bit 4~bit 11)
This register is read only and used for temperature adjusting
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Operating Modes
The device has two operational modes, the Normal mode and the Power Down mode. In the Normal
mode, the high speed system clock may come from external RC (ERC), external crystal (HXT)
or internal RC (HIRC) oscillator. When in the Power down mode, the clocks in this device are all
enabled or disabled using software. The accompanying table illustrates the operating modes and
system clock control.
Operating Mode Control
HALT
Instruction
Mode
System
Oscillator
FSUBC
fSUB Clock
LXTEN
LXT Oscillator
(XT1/XT2)
Not executed
Normal
On
x
Enable
x
On
Power Down
On(OSCON=1)
Off(OSCON=0)
0
Disable
1
On
Power Down
On(OSCON=1)
Off(OSCON=0)
1
Enable
1
On
Power Down
On(OSCON=1)
Off(OSCON=0)
0
Disable
0
Off
Power Down
On(OSCON=1)
Off(OSCON=0)
1
Enable
0
Off
Executed
Note: The LIRCEN1 and LIRCEN0 bits in the WDTC register can be setup to enable the LIRC. If the
LVR is enabled, then the LIRC will also be enabled. However, as the LIRC is powered by the
internal Voltage Regulator, which is controlled by the REGEN bit in the CHPRC register, then
when the REGEN bit is cleared to zero, the LIRC and the LVR will both be disabled. Therefore, the
REGEN bit should be set “1” to enable these two functions. Refer to the WDT section for the details
regarding the WDTOSC setup.
Power Down Mode
The Power down mode is initialised by the “HALT” instruction and results in the following.
●● The system oscillator stops running if the system oscillator is selected to be turned off by
clearing the OSCON bit in the HALTC register to zero. Otherwise, the system oscillator will keep
running if it is selected to be turned on in the power down mode.
●● The contents of the Data Memory and of the registers remain unchanged.
●● The WDT is cleared and starts recounting if the WDT clock source is from the LIRC or the LXT
oscillator.
●● All I/O ports maintain their original status.
●● The PDF flag is set but the TO flag is cleared.
●● The LCD driver keeps running if the LCD clock fSUB is enabled by setting the FSUBC bit high
and the LCDON bit in the HALTC register is set high.
The system leaves the Power down mode by means of an external reset, an interrupt, an
external transition signal on Port A, or a WDT overflow. An external reset causes a device
initialisation, and the WDT overflow performs a “warm reset”. After examining the TO
and PDF flags, the reason for the device reset can be determined. The PDF flag is cleared
by system power-up or by executing the “CLR WDT” instruction, and is set by executing
the “HALT” instruction. On the other hand, the TO flag is set if WDT time-out occurs,
and causes a wake-up that only resets the program counter and SP, and leaves the others in
their original state.
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
The port A wake-up and interrupt methods can be considered as a continuation of normal execution.
Each pin of port A can be independently selected to wake-up the device using configuration
options. After awakening from an I/O port stimulus, the program will resume execution at the next
instruction. However, if awakening from an interrupt, two sequences may occur. If the related
interrupt is disabled or the interrupt is enabled but the stack is full, the program will resume
execution at the next instruction. But if the interrupt is enabled, and the stack is not full, the regular
interrupt response takes place.
When an interrupt request flag is set before entering the “HALT” status, the system cannot be
awakened using that interrupt.
If a wake-up events occur, it takes a number of clock cycles to resume normal operation. In other
words, a dummy period is inserted after the wake-up. If the wake-up results from an interrupt
acknowledgment, the actual interrupt subroutine execution is delayed by more than one cycle.
However, if the wake-up results in the next instruction execution, the execution will be performed
immediately after the dummy period is finished. To minimise power consumption, all the I/O pins
should be carefully managed before entering the HALT status.
The accompanying table illustrates the wake-up delay time for different system clock sources.The
SST time is decided by SST configuration option and the OSCON bit in the HALTC register.
Fsys Clock Source
SST Selection
OSCON
SST Time
( N: number of fsys clock )
0
0
N= 1024
0
1
N= 2
1
0
N= 1024
1
1
N= 2
0
0
N= 1024
0
1
N= 2
1
0
N= 2
1
1
N= 2
0
0
N= 1024
0
1
N= 2
1
0
N= 2
1
1
N= 2
XTAL
ERC
HIRC
Required Wake-up Clock Cycles
HALTC Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
OSCON
—
—
—
—
—
—
LCDON
R/W
R/W
—
—
—
—
—
—
R/W
POR
0
—
—
—
—
—
—
0
bit 7 OSCON: System oscillator state in the Power down mode
0: System oscillator stops running
1: System oscillator keeps running
bit 6~1
unimplemented, read as “0”
bit 0 LCDON: LCD module state in the Power down mode
0: LCD state is determined by the LCD_ON configuration option
1: LCD module remains on (if the fSUB is active) regardless of the configuration
option setting
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Reset and Initialisation
A reset function is a fundamental part of any microcontroller ensuring that the device can be set to
some predetermined condition irrespective of outside parameters. The most important reset condition
is after power is first applied to the microcontroller. In this case, internal circuitry will ensure that
the microcontroller, after a short delay, will be in a well defined state and ready to execute the first
program instruction. After this power-on reset, certain important internal registers will be set to
defined states before the program commences.
One of these registers is the Program Counter, which will be reset to zero forcing the microcontroller
to begin program execution from the lowest Program Memory address. In addition to the poweron reset, situations may arise where it is necessary to forcefully apply a reset condition when the
microcontroller is running. One example of this is where after power has been applied and the
microcontroller is already running, the RES line is forcefully pulled low. In such a case, known
as a normal operation reset, some of the microcontroller registers remain unchanged allowing the
microcontroller to proceed with normal operation after the reset line is allowed to return high.
Another type of reset is when the Watchdog Timer overflows and resets the microcontroller. All
types of reset operations result in different register conditions being setup. Another reset exists in
the form of a Low Voltage Reset, LVR, where a full reset, similar to the RES reset is implemented in
situations where the power supply voltage falls below a certain threshold.
Reset Functions
There are five ways in which a microcontroller reset can occur, through events occurring both
internally and externally:
Power-on Reset
The most fundamental and unavoidable reset is the one that occurs after power is first applied to
the microcontroller. As well as ensuring that the Program Memory begins execution from the first
memory address, a power-on reset also ensures that certain other registers are preset to known
conditions. All the I/O port and port control registers will power up in a high condition ensuring that
all pins will be first set to inputs.
Note: tRSTD is power-on delay, typical time=100ms
Power-On Reset Timing Chart
For the application a resistor connected between VDD and the RES pin and a capacitor connected
between VSS and the RES pin will provide a suitable external reset circuit. Any wiring connected
to the RES pin should be kept as short as possible to minimise any stray noise interference. For the
application that operates within an environment where more noise is present the Enhanced Reset
Circuit shown is recommended.
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Note: “*” It is recommended that this component is added ESD protection.
“**” It is recommended that this component is added in environments where power line
noise is significant.
External RES Circuit
More information regarding external reset circuits is located in Application Note HA0075E on the
Holtek website
RES Pin Reset
This type of reset occurs when the microcontroller is already running and the RES pin is forcefully
pulled low by external hardware such as an external switch. In this case as in the case of other reset,
the Program Counter will reset to zero and program execution initiated from this point.
Note: tRSTD is power-on delay, typical time= 100ms
RES Reset Timing Chart
Low Voltage Reset – LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of
the device. The LVR function has a specific LVR voltage VLVR. If the supply voltage of the device
drops to within a range of 0.9V~VLVR such as might occur when changing the battery, the LVR will
automatically reset the device internally and the LVRF bit in the WDTC1 register will also be set
to 1. The LVR includes the following specifications: For a valid LVR signal, a low voltage, i.e., a
voltage in the range between 0.9V~VLVR must exist for greater than the value tLVR specified in the
A.C. characteristics. If the low voltage state does not exceed tLVR, the LVR will ignore it and will
not perform a reset function. One of a range of specified voltage values for VLVR can be selected by
the LVS bits in the LVRC register. If the LVS7~LVS0 bits have any other value, which may perhaps
occur due to adverse environmental conditions such as noise, the LVR will reset the device after 2~3
LIRC clock cycles. When this happens, the LRF bit in the WDTC1 register will be set to 1. After
power on the register will have the value of 01010101B.
Note that the LVR function will be automatically disabled when the device enters the power down
mode.
Note: tRSTD is power-on delay, typical time= 100ms
Low Voltage Reset Timing Chart
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●● LVRC Register
Bit
7
6
5
4
3
2
1
0
Name
LVS7
LVS6
LVS5
LVS4
LVS3
LVS2
LVS1
LVS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
1
0
1
0
1
0
1
Bit 7~0
LVS7 ~ LVS0: LVR voltage select
01010101: 2.1V (default)
00110011: 2.55V
10011001: 3.15V
10101010: 3.8V
Other values: Generates MCU reset – register is reset to POR value
When an actual low voltage condition occurs, as specified by one of the four defined
LVR voltage values above, an MCU reset will be generated. The reset operation will
be activated after 2~3 LIRC clock cycles. In this situation the register contents will
remain the same after such a reset occurs.
Any register value, other than the four defined register values above, will also result in
the generation of an MCU reset. The reset operation will be activated after 2~3 LIRC
clock cycles. However in this situation the register contents will be reset to the POR
value.
Watchdog Time-out Reset during Normal Operation
The Watchdog time-out Reset during normal operation is the same as a hardware RES pin reset
except that the Watchdog time-out flag TO will be set to “1”.
Note: tRSTD is power-on delay, typical time= 100ms
WDT Time-out Reset during Normal Operation Timing Chart
Watchdog Time-out Reset during Power Down mode
The Watchdog time-out Reset during power down mode is a little different from other kinds of reset.
Most of the conditions remain unchanged except that the Program Counter and the Stack Pointer
will be cleared to “0” and the TO flag will be set to “1”. Refer to the A.C. Characteristics for tSST
details.
Note: The tSST can be chosen to be either 1024 or 2 clock cycles via configuration option if the
system clock source is provided by ERC or HIRC. The SST is 1024 for HXT or LXT.
WDT Time-out Reset during Power down Timing Chart
Reset Initial Conditions
The different types of reset described affect the reset flags in different ways. These flags, known as PDF
and TO are located in the status register and are controlled by various microcontroller operations, such
as the Power down function or Watchdog Timer. The reset flags are shown in the table.
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TO
PDF
0
0
Power-on reset
RESET Conditions
u
u
RES or LVR reset during Normal operation
0
1
RES Wake-up HALT
1
u
WDT time-out reset during Normal operation
1
1
WDT Wake-up HALT
Note: “u” stands for unchanged.
The following table indicates the way in which the various components of the microcontroller are
affected after a power-on reset occurs.
Item
Condition After RESET
Program Counter
Reset to zero
Interrupts
All interrupts will be disabled
WDT
Clear after reset, WDT begins counting
Timer/Event Counter
Timer Counter will be turned off
Prescaler
The Timer Counter Prescaler will be cleared
Input/output Ports
I/O ports will be setup as inputs
Stack Pointer
Stack Pointer will point to the top of the stack
The different kinds of resets all affect the internal registers of the microcontroller in different ways.
To ensure reliable continuation of normal program execution after a reset occurs, it is important to
know what condition the microcontroller is in after a particular reset occurs. The following table
describes how each type of reset affects each of the microcontroller internal registers.
Register
Rev. 1.20
Reset
(Power On)
----
WDT Time-out
(Normal
Operation)
---- ----
RES Reset
(Normal
Operation)
---- ----
----
RES Reset
(HALT)
IAR0
----
MP0
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
IAR1
----
----
----
----
----
MP1
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
BP
---0 --00
---0 --00
---0 --00
---0 --00
---u --uu
ACC
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
PCL
----
----
----
----
----
TBLP
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLH
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
CTRL0
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
STATUS
--00 xxxx
--1u uuuu
--uu uuuu
--01 uuuu
- - 11 u u u u
INTC0
-000 0000
-000 0000
-000 0000
-000 0000
-uuu uuuu
LVRC
0101 0101
0101 0101
0101 0101
0101 0101
uuuu uuuu
TMR0
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR0C
0000 1000
0000 1000
0000 1000
0000 1000
uuuu uuuu
TMR1H
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR1L
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR1C
0000 1000
0000 1000
0000 1000
0000 1000
uuuu uuuu
PA
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PAC
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PB
- - 11 1111
- - 11 1111
- - 11 1111
- - 11 1111
--uu uuuu
PBC
- - 11 1111
- - 11 1111
- - 11 1111
- - 11 1111
--uu uuuu
----
----
----
----
39
----
----
----
WDT Time-out
(HALT)*
----
----
----
-------
----
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HT45R2K-C/-B/-A
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DACO
--00 0000
WDT Time-out
(Normal
Operation)
--00 0000
--00 0000
--uu uuuu
FTRC
0--0 --00
0--0 --00
0--0 --00
0--0 --00
u--u --uu
ADCR
-000 x000
-000 x000
-000 x000
-000 x000
-uuu uuuu
SWC
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
ADCD
0 0 0 0 - 111
0 0 0 0 - 111
0 0 0 0 - 111
0 0 0 0 - 111
uuuu -uuu
WDTC1
0 1 0 1 0 x 11
0 1 0 1 0 x 11
0 1 0 1 0 x 11
0 1 0 1 0 x 11
uuuu uuuu
WDTC
111 - s s 0 1
111 - s s 0 1
111 - s s 0 1
111 - s s 0 1
uuu- uuuu
WDTD
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTC1
-000 -000
-000 -000
-000 -000
-000 -000
-uuu –uuu
CHPRC
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TMR2H
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR2L
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR2C
0000 1000
0000 1000
0000 1000
0000 1000
uuuu uuuu
SGC
0--0 ----
0--0 ----
0--0 ----
0--0 ----
u--u ----
SGDNR
---0 0000
---0 0000
---0 0000
---0 0000
---u uuuu
SGN
--00 0000
--00 0000
--00 0000
--00 0000
--uu uuuu
HALTC
0--- ---0
0--- ---0
0--- ---0
0--- ---0
u--- ---u
LCDOUT
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
CTRL1
00-- --01
00-- --01
00-- --01
00-- --01
uu-- --uu
VIBRC
---- ---0
---- ---0
---- ---0
---- ---0
---- ---u
IADAC
0-00 0000
0-00 0000
0-00 0000
0-00 0000
u-uu uuuu
PC
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PCC
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PAWK
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
PAPU
-000 0000
-000 0000
-000 0000
-000 0000
-uuu uuuu
PBPU
--00 0000
--00 0000
--00 0000
--00 0000
--uu uuuu
PCPU
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
SFS
---- --00
---- --00
---- --00
---- --00
---- --uu
OPAC
0--- 0000
0--- 0000
0--- 0000
0--- 0000
u--- uuuu
LCDC
00-0 -000
00-0 -000
00-0 -000
00-0 -000
uu-u -uuu
MFIC
-000 -000
-000 -000
-000 -000
-000 -000
-uuu -uuu
IAC0
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
IAC1
1111 0 0 - 1
1111 0 0 - 1
1111 0 0 - 1
1111 0 0 - 1
uuuu uu-u
TKM0C4
-000 ---0
-000 ---0
-000 ---0
-000 ---0
-uuu ---u
TKM016DH
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TKM016DL
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TKM010DL
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TKM0RO
0000 0001
0000 0001
0000 0001
0000 0001
uuuu uuuu
TKM0C0
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TKM0C1
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TKM0C2
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
TKM0C3
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
Register
Reset
(Power On)
RES Reset
(Normal
Operation)
--00 0000
RES Reset
(HALT)
WDT Time-out
(HALT)*
Note : *stands for “warm reset”
"-" not implement
"u" stands for "unchanged"
"x" stands for "unknown"
"s" for special case, it depends on the option table (please see the WDT chapter for the detail)
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Input/Output Ports
Holtek microcontrollers offer considerable flexibility on their I/O ports. Most pins can have either an
input or output designation under user program control. Additionally, as there are pull-high resistors
and wake-up software configurations, the user is provided with an I/O structure to meet the needs of
a wide range of application possibilities.
For input operation, these ports are non-latching, which means the inputs must be ready at the T2
rising edge of instruction "MOV A, [m]", where m denotes the port address. For output operation,
all the data is latched and remains unchanged until the output latch is rewritten.
I/O Register List
Register
Name
Bit
POR
7
6
5
4
3
2
1
0
PAWK0
PAWK
00H
PAWK7
PAWK6
PAWK5
PAWK4
PAWK3
PAWK2
PAWK1
PAC
FFH
PAC7
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC0
PAPU
00H
—
PAPU6
PAPU5
PAPU4
PAPU3
PAPU2
PAPU1
PAPU0
PBC
3FH
—
—
PBC5
PBC4
PBC3
PBC2
PBC1
PBC0
PBPU
00H
—
—
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
PCC
FFH
PCC7
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC0
PCPU
FFH
PCPU7
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU0
Pull-high Resistors
Many product applications require pull-high resistors for their switch inputs usually requiring the
use of an external resistor. To eliminate the need for these external resistors, when configured as
an input have the capability of being connected to an internal pull-high resistor. These pull-high
resistors are selectable via a register known as PAPU, PBPU and PCPU located in the Data Memory.
The pull-high resistors are implemented using weak PMOS transistors. Note that pin PA7 does not
have a pull-high resistor selection.
PAPU Register
Bit
7
6
5
4
3
2
1
0
Name
—
PAPU6
PAPU5
PAPU4
PAPU3
PAPU2
PAPU1
PAPU0
R/W
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
0
0
0
0
0
0
0
Bit 7
Unimplemented, read as “0”
Bit 6~0
PAPU: I/O Port bit 6 ~ bit 0 Pull-High Control
0: Disable
1: Enable
PBPU Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
0
0
0
0
0
0
Bit 7~6
Unimplemented, read as “0”
Bit 5~0
PBPU: I/O Port bit5 ~ bit 0 Pull-High Control
0: Disable
1: Enable
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
PCPU Register
Bit
7
6
5
4
3
2
1
0
Name
PCPU7
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
1
1
1
1
1
1
1
1
PCPU: I/O Port bit 7 ~ bit 0 Pull-High Control
Bit 7~0
0: Disable
1: Enable
Port A Wake-up
If the HALT instruction is executed, the device will enter Power down mode, where the system
clock will stop resulting in power being conserved, a feature that is important for battery and other
low-power applications. Various methods exist to wake-up the microcontroller, one of which is to
change the logic condition on one of the PA0~PA7 pins from high to low. After a HALT instruction
forces the microcontroller into entering Power down mode, the processor will remain in a low-power
state until the logic condition of the selected wake-up pin on Port A changes from high to low. This
function is especially suitable for applications that can be woken up via external switches. Note that
pins PA0 to PA7 can be selected individually to have this wake-up feature using an internal register
known as PAWK, located in the Data Memory.
PAWU Register
Bit
7
6
5
4
3
2
1
0
Name
PAWK7
PAWK6
PAWK5
PAWK4
PAWK3
PAWK2
PAWK1
PAWK0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~0
PAWU: Port A bit 7 ~ bit 0 Wake-up Control
0: Disable
1: Enable
I/O Port Control Registers
Each Port has its own control register, known as PAC, PBC and PCC which controls the input/
output configuration. With this control register, each I/O pin with or without pull-high resistors can
be reconfigured dynamically under software control. For the I/O pin to function as an input, the
corresponding bit of the control register must be written as a “1”. This will then allow the logic state of
the input pin to be directly read by instructions. When the corresponding bit of the control register is
written as a “0”, the I/O pin will be setup as a CMOS output. If the pin is currently setup as an output,
instructions can still be used to read the output register. However, it should be noted that the program
will in fact only read the status of the output data latch and not the actual logic status of the output pin.
PAC Register
Bit
7
6
5
4
3
2
1
0
Name
PAC7
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
1
1
1
1
1
1
1
1
Bit 7~0
PAC: I/O Port bit 7 ~ bit 0 Input/Output Control
0: Output
1: Input
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
PBC Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
PBC5
PBC4
PBC3
PBC2
PBC1
PBC0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
1
1
1
1
1
1
Bit 7~6
“—” Unimplemented, read as “0”
Bit 5~0
PBC: I/O Port bit 5 ~ bit 0 Input/Output Control
0: Output
1: Input
PCC Register
Bit
7
6
5
4
3
2
1
0
Name
PCC7
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
1
1
1
1
1
1
1
1
Bit 7~0
PCC: I/O Port bit 7 ~ bit 0 Input/Output Control
0: Output
1: Input
Pin-shared Functions
The flexibility of the microcontroller range is greatly enhanced by the use of pins that have more
than one function. Limited numbers of pins can force serious design constraints on designers but by
supplying pins with multi-functions, many of these difficulties can be overcome. For some pins, the
chosen function of the multi-function I/O pins is set by configuration options while for others the
function is set by application program control.
External Interrupt Input
The external interrupt pin, INT, is pin-shared with an I/O pin. To use the pin as an external interrupt
input the correct bits in the INTC0 register must be programmed. The pin must also be setup as an
input by setting the PBC4 bit in the Port Control Register. A pull-high resistor can also be selected
via the appropriate port pull-high resistor register. Note that even if the pin is setup as an external
interrupt input the I/O function still remains.
External Timer/Event Counter Input
The Timer/Event Counter pins, TMR0, TMR1 and TMR2 are pin-shared with I/O pins. For these
shared pins to be used as Timer/Event Counter inputs, the Timer/Event Counter must be configured
to be in the Event Counter or Pulse Width Measurement Mode. This is achieved by setting the
appropriate bits in the Timer/Event Counter Control Register. The pins must also be setup as inputs
by setting the appropriate bit in the Port Control Register. Pull-high resistor options can also be
selected using the port pull-high resistor registers. Note that even if the pin is setup as an external
timer input the I/O function still remains.
Buzzer Output
The buzzer function output is pin-shared with an I/O pin. The output function of this pin is chosen
using the SFS register. Note that the corresponding bit of the port control register, must setup the
pin as an output to enable buzzer output. If the port control register has setup the pin as an input,
then the pin will function as a normal logic input with the usual pull-high selection, even if buzzer
function has been selected.
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
LCD Driver Pins
Pins PC0~PC7 on Port C can be used as LCD SEG driver pins. This function is controlled using the
LCDOUT register.
Touch Key Pins
Pins PB0~PB3 are pin-shared with touch key function. This function is controlled using the
TKM0C2 register.
I/O Pin Structures
The diagrams illustrate the I/O pin internal structures. As the exact logical construction of the I/O
pin may differ from these drawings, they are supplied as a guide only to assist with the functional
understanding of the I/O pins.

Generic Input/Output Ports

PA7 NMOS Input/Output Port
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Programming Considerations
Within the user program, one of the first things to consider is port initialisation. After a reset, the I/
O data register and I/O port control register will be set high. This means that all I/O pins will default
to an input state, the level of which depends on the other connected circuitry and whether pull-high
options have been selected. If the port control registers, are then programmed to setup some pins
as outputs, these output pins will have an initial high output value unless the associated port data
register is first programmed. Selecting which pins are inputs and which are outputs can be achieved
byte-wide by loading the correct value into the port control register or by programming individual
bits in the port control register using the “SET [m].i” and “CLR [m].i” instructions. Note that when
using these bit control instructions, a read-modify-write operation takes place. The microcontroller
must first read in the data on the entire port, modify it to the required new bit values and then rewrite
this data back to the output ports.
Read Modify Write Timing
Pins PA0 to PA7 each have a wake-up function, selected via the PAWK register. When the device is
in the Idle/Sleep Mode, various methods are available to wake the device up. One of these is a high to
low transition of any of these pins. Single or multiple pins on Port A can be setup to have this function.
Timer/Event Counters
Three timer/event counters are implemented in the microcontroller. Timer/Event Counter 0 contains
an 8-bit programmable count-up counter whose clock may come from an external source or an
internal clock source. An internal clock source comes from fSYS or the internal low frequency clock
known as fL. Timer/Event Counter 1 contains a 16-bit programmable count-up counter whose clock
may come from an external source or an internal clock source. An internal clock source comes
from fSYS/4 or the internal low frequency clock known as fL. The clock fL is derived from the LIRC
or LXT oscillator and can be selected by the Low Frequency selection bit LFS bit in the CTRL0
register. The external clock input allows the user to count external events, measure time intervals
or pulse widths, or to generate an accurate time base. Timer/Event Counter 2 contains a 16-bit
programmable count-up counter whose clock may come from an external source or an internal clock
source. An internal clock source comes from fSYS/4 or the Timer/Event Counter 2 internal clock fTCK.
The clock fTCK may come from the low frequency clock fL or the clocks generated from the Touch
Key module named fREF, fSEN and fTMCK described in the Touch Key Function section. The clock
is selected using the Timer/Event Counter 2 clock source selection bits TCKS1 and TCK0 in the
CTRL0 register. The external clock input allows the user to count external events, measure time
intervals or pulse widths, or to generate an accurate time base.
There are two registers related to the Timer/Event Counter 0; TMR0 and TMR0C.Writing to TMR0
puts the starting value in the Timer/Event Counter 0 register and reading TMR0 reads out the
contents of Timer/Event Counter 0. The TMR0C is a timer/event counter control register, which
defines the overall operations. There are three registers related to the Timer/Event Counter 1;
TMR1H, TMR1L and TMR1C. Writing to TMR1L will only put the written data into an internal
lower-order byte buffer (8-bit) while writing to TMR1H will transfer the specified data and the
contents of the lower-order byte buffer to both the TMR1H and TMR1L registers, respectively.
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
The Timer/Event Counter 1 preload register is changed when each time there is a write operation
to TMR1H. Reading TMR1H will latch the contents of TMR1H and TMR1L counters to the
destination and the lower-order byte buffer, respectively. Reading TMR1L will read the contents of
the lower-order byte buffer. TMR1C is the Timer/Event Counter 1 control register, which defines the
operating mode, counting enable or disable, the TMR1 active edge and the prescaler stage selections.
Also there are three registers related to the Timer/Event Counter 2 named TMR2H, TMR2L and
TMR2C. The operations of reading from and writing to the Timer/Event Counter 2 registers named
TMR2H and TMR2L are the same with Timer/Event Counter 1 described above.
The TxM0 and TxM1 bits in TMRxC register where x may be equal to 0, 1 or 2 define the operation
mode. The event count mode is used to count external events, which means that the clock source
must come from the external (TMR0, TMR1 or TMR2) pin. The timer mode functions as a normal
timer with the clock source coming from the internal selected clock source.
Finally, the pulse width measurement mode can be used to count a high or low level duration of an
external signal on the TMR0, TMR1 or TMR2 pins with the timing based on the internally selected
clock source. In the event count or timer mode, the Timer/Event Counter starts counting at the
current contents in the Timer/Event Counter and ends at FFH for -8-bit counter or FFFFH for 16bit counter. Once an overflow occurs, the counter is reloaded from the timer/event counter preload
register, and generates an interrupt request flag, T0F, T1F or T2F. In the pulse width measurement
mode with the values of the Timer enable control bit TxON and the active edge control bit TxE
equal to “1”, after the TMRx pin has received a transient from low to high (or high to low if the TxE
bit is “0”), it will start counting until the TMRx pin returns to the original level and resets the TxON
bit. The measured result remains in the timer/event counter even if the activated transient occurs
again. Therefore, only a 1-cycle measurement can be made until the TxON bit is again set. The cycle
measurement will re-function as long as it receives further transient pulses. In this operation mode,
the timer/event counter begins counting not according to the logic level but to the transient edges.
In the case of counter overflows, the counter is reloaded from the timer/event counter register and
issues an interrupt request, as in the other two modes, i.e., event and timer modes.

Timer/Event Count 0

Timer/Event Count 1
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale

Timer/Event Count 2
TMR0C Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
T0M1
T0M0
T0S
T0ON
T0E
T0PSC2
T0PSC1
T0PSC0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
1
0
0
0
Bit 7~6
T0M1, T0M0: Timer0 operation mode selection
00: no mode available
01: event counter mode
10: timer mode
11: pulse width measurement mode
Bit 5
T0S: timer clock source
0: fSYS
1: Low Frequency clock fL
Bit 4 T0ON: Timer/event counter counting enable
0: disable
1: enable
Bit 3 T0E:
Event Counter active edge selection
0: count on rising edge
1: count on falling edge
Pulse Width measurement active edge selection
0: start counting on falling edge, stop on rising edge
1: start counting on rising edge, stop on falling edge
Bit 2~0 T0PSC2, T0PSC1, T0PSC0: Timer prescaler rate selection
Timer internal clock (fINT0)=
000: fT0
001: fT0/2
010: fT0/4
011: fT0/8
100: fT0/16
101: fT0/32
110: fT0/64
111: fT0/128
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
TMR1C Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
T1M1
T1M0
T1S
T1ON
T1E
T1PSC2
T1PSC1
T1PSC0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
1
0
0
0
Bit 7~6
T1M1, T1M0: Timer0 operation mode selection
00: no mode available
01: event counter mode
10: timer mode
11: pulse width measurement mode
Bit 5
T1S: timer clock source
0: fSYS/4
1: Low Frequency clock fL
Bit 4 T1ON: Timer/event counter counting enable
0: disable
1: enable
Bit 3 T1E:
Event Counter active edge selection
0: count on rising edge
1: count on falling edge
Pulse Width measurement active edge selection
0: start counting on falling edge, stop on rising edge
1: start counting on rising edge, stop on falling edge
Bit 2~0 T1PSC2, T1PSC1, T1PSC0: Timer prescaler rate selection
Timer internal clock (fINT1)=
000: fT1
001: fT1/2
010: fT1/4
011: fT1/8
100: fT1/16
101: fT1/32
110: fT1/64
111: fT1/128
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
TMR2C Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
T2M1
T2M0
T2S
T2ON
T2E
T2PSC2
T2PSC1
T2PSC0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
1
0
0
0
Bit 7~6
T2M1, T2M0: Timer0 operation mode selection
00: no mode available
01: event counter mode
10: timer mode
11: pulse width measurement mode
Bit 5
T2S: Timer clock source
0: fSYS/4
1: fTCK
Bit 4 T2ON: Timer/event counter counting enable
0: disable
1: enable
Bit 3 T2E:
Event Counter active edge selection
0: count on rising edge
1: count on falling edge
Pulse Width Measurement active edge selection
0: start counting on falling edge, stop on rising edge
1: start counting on rising edge, stop on falling edge
Bit 2~0 T2PSC2, T2PSC1, T2PSC0: Timer prescaler rate selection
Timer internal clock (fINT2)=
000: fT2
001: fT2/2
010: fT2/4
011: fT2/8
100: fT2/16
101: fT2/32
110: fT2/64
111: fT2/128
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Timer Mode
In this mode, the Timer/Event Counter can be utilised to measure fixed time intervals, providing
an internal interrupt signal each time the Timer/Event Counter overflows. To operate in this mode,
the Operating Mode Select bit pair, TnM1/TnM0, in the Timer Control Register must be set to the
correct value as shown.
Control Register Operating Mode Select Bits for the Timer Mode
Bit7
Bit6
1
0
In this mode the internal clock is used as the timer clock. The timer input clock source is either
fSYS, fSYS/4, fL or fTCK. However, this timer clock source is further divided by a prescaler, the value of
which is determined by the bits TnPSC2~TnPSC0 in the Timer Control Register. The timer-on bit,
TnON must be set high to enable the timer to run. Each time an internal clock high to low transition
occurs, the timer increments by one; when the timer is full and overflows, an interrupt signal is
generated and the timer will reload the value already loaded into the preload register and continue
counting. A timer overflow condition and corresponding internal interrupt is one of the wake-up
sources, however, the internal interrupts can be disabled by ensuring that the ETnI bits of the INTC0
and MFIC register are reset to zero.
Timer Mode Timing Chart
Event Counter Mode
In this mode, a number of externally changing logic events, occurring on the external timer TMRn
pin, can be recorded by the Timer/Event Counter. To operate in this mode, the Operating Mode
Select bit pair, TnM1/TnM0, in the Timer Control Register must be set to the correct value as
shown.
Control Register Operating Mode Select Bits for the Event Counter Mode
Bit7
Bit6
0
1
In this mode, the external timer TMRn pin is used as the Timer/Event Counter clock source,
however it is not divided by the internal prescaler. After the other bits in the Timer Control Register
have been setup, the enable bit TnON, which is bit 4 of the Timer Control Register, can be set high
to enable the Timer/Event Counter to run. If the Active Edge Select bit, TnE, which is bit 3 of the
Timer Control Register, is low, the Timer/Event Counter will increment each time the external timer
pin receives a low to high transition. If the TnE is high, the counter will increment each time the
external timer pin receives a high to low transition. When it is full and overflows, an interrupt signal
is generated and the Timer/Event Counter will reload the value already loaded into the preload
register and continue counting. The interrupt can be disabled by ensuring that the Timer/Event
Counter Interrupt Enable bit in the corresponding Interrupt Control Register is reset to zero.
As the external timer pin is shared with an I/O pin, to ensure that the pin is configured to operate as
an event counter input pin, two things have to happen. The first is to ensure that the Operating Mode
Select bits in the Timer Control Register place the Timer/Event Counter in the Event Counting
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Mode, the second is to ensure that the port control register configures the pin as an input. It should
be noted that in the event counting mode, even if the is in the Power Down Mode, the Timer/Event
Counter will continue to record externally changing logic events on the timer input TMRn pin. As a
result when the timer overflows it will generate a timer interrupt and corresponding wake-up source.
Event Counter Mode Timing Chart (TnE=1)
Pulse Width Measurement Mode
In this mode, the Timer/Event Counter can be utilised to measure the width of external pulses
applied to the external timer pin. To operate in this mode, the Operating Mode Select bit pair, TnM1/
TnM0, in the Timer Control Register must be set to the correct value as shown.
Control Register Operating Mode Select Bits for the Pulse Width Capture Mode
Bit7
Bit6
1
1
In this mode the internal clock, fSYS, fSYS/4, fL or fTCK, is used as the internal clock for the 8-bit
Timer/Event Counter and the 16-bit Timer/Event Counter. However, the clock source, fSYS and
fSYS/4, for the 8-bit timer and the 16-bit timer are further divided by a prescaler, the value of which
is determined by the Prescaler Rate Select bits TnPSC2~TnPSC0, which are bits 2~0 in the Timer
Control Register. After the other bits in the Timer Control Register have been setup, the enable
bit TnON, which is bit 4 of the Timer Control Register, can be set high to enable the Timer/Event
Counter, however it will not actually start counting until an active edge is received on the external
timer pin.
If the Active Edge Select bit TnE, which is bit 3 of the Timer Control Register, is low, once a high
to low transition has been received on the external timer pin, the Timer/Event Counter will start
counting until the external timer pin returns to its original high level. At this point the enable bit will
be automatically reset to zero and the Timer/Event Counter will stop counting. If the Active Edge
Select bit is high, the Timer/Event Counter will begin counting once a low to high transition has
been received on the external timer pin and stop counting when the external timer pin returns to its
original low level. As before, the enable bit will be automatically reset to zero and the Timer/Event
Counter will stop counting. It is important to note that in the pulse width measurement Mode, the
enable bit is automatically reset to zero when the external control signal on the external timer pin
returns to its original level, whereas in the other two modes the enable bit can only be reset to zero
under program control. The residual value in the Timer/Event Counter, which can now be read by
the program, therefore represents the length of the pulse received on the TMRn pin. As the enable
bit has now been reset, any further transitions on the external timer pin will be ignored. The timer
cannot begin further pulse width measurement until the enable bit is set high again by the program.
In this way, single shot pulse measurements can be easily made.
It should be noted that in this mode the Timer/Event Counter is controlled by logical transitions
on the external timer pin and not by the logic level. When the Timer/Event Counter is full and
overflows, an interrupt signal is generated and the Timer/Event Counter will reload the value already
loaded into the preload register and continue counting. The interrupt can be disabled by ensuring
that the Timer/Event Counter Interrupt Enable bit in the corresponding Interrupt Control Register, is
reset to zero.
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
As the TMRn pin is shared with an I/O pin, to ensure that the pin is configured to operate as a
pulse width measurement pin, two things have to happen. The first is to ensure that the Operating
Mode Select bits in the Timer Control Register place the Timer/Event Counter in the pulse width
measurement mode, the second is to ensure that the port control register configures the pin as an
input.

Pulse Width Measurement Mode Timing Chart (TnE=0)
Prescaler
Bits TnPSC0~TnPSC2 of the TMRnC register can be used to define a division ratio for the internal
clock source of the Timer/Event Counter enabling longer time out periods to be setup.
Buzzer
Operating in a similar way to the Programmable Frequency Divider, the Buzzer function provides
a means of producing a variable frequency output, suitable for applications such as Piezo-buzzer
driving or other external circuits that require a precise frequency generator. The BZ and BZ pins
form a complimentary pair, and are pin-shared with I/O pins, PA1 and PA2. Note that the BZ pin
is the inverse of the BZ pin which together generates a differential output which can supply more
power to connected interfaces such as buzzers. The PA1 and PA2 are setup as I/O pins or buzzer pins
using the SFS register.
The buzzer is driven by the Timer/Event Counter 0 or Timer/Event Counter 1 overflow signal
divided by 2 selected by the clock source selection bit named BZCS in CTRL1 register.
If the software options have selected both pins PA1 and PA2 to function as a BZ and BZ
complementary pair of buzzer outputs, then for correct buzzer operation it is essential that both pins
must be setup as outputs by setting bits PAC1 and PAC2 of the PAC port control register to zero.
The PA1 data bit in the PA data register must also be set high to enable the buzzer outputs, if set low,
both pins PA1 and PA2 will remain low. In this way the single bit PA1 of the PA data register can be
used as an on/off control for both the BZ and BZ buzzer pin outputs. Note that the PA2 data bit in
the PA data register has no control over the BZ buzzer pin PA2.
If software options have selected that only the PA1 pin is to function as a BZ buzzer pin, then the
PA2 pin can be used as a normal I/O pin. For the PA1 pin to function as a BZ buzzer pin, PA1 must
be setup as an output by setting bit PAC1 of the PAC port control register to zero. The PA1 data
bit in the PA data register must also be set high to enable the buzzer output, if set low pin PA1 will
remain low. In this way the PA1 bit can be used as an on/off control for the BZ buzzer pin PA1. If
the PAC1 bit of the PAC port control register is set high, then pin PA1 can still be used as an input
even though the Software option has configured it as a BZ buzzer output.
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
BZBS
BZS
PAC2
PAC1
PA2
PA1
1
1
0
0
X
1
PA1= BZ, PA2= BZ
Function
1
1
0
0
X
0
PA1= "0", PA2= "0"
1
1
0
1
X
1
PA1= "Input", PA2= BZ
1
1
0
1
X
0
PA1= "Input", PA2= "0"
1
1
1
0
X
1
PA1= BZ, PA2= "Input"
1
1
1
0
X
0
PA1= "0", PA2= "Input"
X
X
1
1
X
X
PA1= "Input", PA2= "Input"
0
0
X
X
X
X
PA1= "I/O", PA2= "I/O"
"×" stands for don’t care
SFS Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
BZBS
BZS
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
0
0
Bit 7~2 Unimplemented, read as “0”
Bit 1
BZBS: PA2 function selection
Bit 0 BZS: PA1 function selection
0: I/O
1: BZ
0: I/O
1: BZ
When register “SFS” selects the I/O function, the related control refers to the Port A
control register.
T im e r O v e r flo w
B u z z e r C lo c k
P A 1 D a ta
B Z O u tp u t a t P A 1
B Z O u tp u t a t P A 2
Buzzer Output Pin Control
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
I/O Interfacing
The Timer/Event Counter, when configured to run in the event counter or pulse width measurement
mode, requires the use of an external timer pin for its operation. As this pin is a shared pin it must
be configured correctly to ensure that it is setup for use as a Timer/Event Counter input pin. This is
achieved by ensuring that the mode select bits in the Timer/Event Counter control register, select
either the event counter or pulse width measurement mode. Additionally the corresponding Port
Control Register bit must be set high to ensure that the pin is setup as an input. Any pull-high
resistor connected to this pin will remain valid even if the pin is used as a Timer/Event Counter
input.
Programming Considerations
When configured to run in the timer mode, the internal system clock is used as the timer clock
source and is therefore synchronised with the overall operation of the microcontroller. In this mode
when the appropriate timer register is full, the microcontroller will generate an internal interrupt
signal directing the program flow to the respective internal interrupt vector. For the pulse width
measurement mode, the internal system clock is also used as the timer clock source but the timer
will only run when the correct logic condition appears on the external timer input pin. As this is
an external event and not synchronised with the internal timer clock, the microcontroller will only
see this external event when the next timer clock pulse arrives. As a result, there may be small
differences in measured values requiring programmers to take this into account during programming.
The same applies if the timer is configured to be in the event counting mode, which again is an
external event and not synchronised with the internal system or timer clock.
When the Timer/Event Counter is read, or if data is written to the preload register, the clock is
inhibited to avoid errors, however as this may result in a counting error, this should be taken into
account by the programmer. Care must be taken to ensure that the timers are properly initialised
before using them for the first time. The associated timer enable bits in the interrupt control
register must be properly set otherwise the internal interrupt associated with the timer will remain
inactive. The edge select, timer mode and clock source control bits in timer control register must
also be correctly set to ensure the timer is properly configured for the required application. It is
also important to ensure that an initial value is first loaded into the timer registers before the timer
is switched on; this is because after power-on the initial values of the timer registers are unknown.
After the timer has been initialised the timer can be turned on and off by controlling the enable bit in
the timer control register.
When the Timer/Event Counter overflows, its corresponding interrupt request flag in the interrupt
control register will be set. If the Timer/Event Counter interrupt is enabled this will in turn generate
an interrupt signal. However irrespective of whether the interrupts are enabled or not, a Timer/Event
Counter overflow will also generate a wake-up signal if the device is in a Power-down condition.
This situation may occur if the Timer/Event Counter is in the Event Counting Mode and if the
external signal continues to change state. In such a case, the Timer/Event Counter will continue to
count these external events and if an overflow occurs the device will be woken up from its Powerdown condition. To prevent such a wake-up from occurring, the timer interrupt request flag should
first be set high before issuing the “HALT” instruction to enter the Idle/Sleep Mode.
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Timer Program Example
The program shows how the Timer/Event Counter registers are setup along with how the interrupts
are enabled and managed. Note how the Timer/Event Counter is turned on, by setting bit 4 of the
Timer Control Register. The Timer/Event Counter can be turned off in a similar way by clearing the
same bit. This example program sets the Timer/Event Counters to be in the timer mode, which uses
the internal system clock as their clock source.
PFD Programming Example
org 04h
;external interrupt vector
org 0ch
;Timer Counter 0 interrupt vector
jmp tmr0int;jump here when Timer 0 overflows
:
:
org 20h
;main program
:
:
;internal Timer 0 interrupt routine
tmr0int:
:
:
;Timer 0 main program placed here
:
:
begin:
;setup Timer 0 registers
mov a,09bh ;setup Timer 0 preload value
mov tmr0,a
mov a,081h ;setup Timer 0 control register
mov tmr0c,a
;timer mode and prescaler set to /2
;setup interrupt register
mov a,005h ;enable master interrupt and both timer interrupts
mov intc0,a
:
:
set tmr0c.4
;start Timer 0
:
:
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Vibration Sensor Amplifier
The device contains a Vibration Sensor Amplifier to amplify small signal inputs, generated from
vibration sensors. When the sensor is connected to the vibration input pin, namely VIB, and a small
signal resulting from vibration detection is generated on the VIB pin, the internal amplifier will
amplify the signal to generate a wake-up source to wake up the device from the power down mode.
The Vibration Sensor Amplifier can be enabled or disable by the control bit, VIBREN, in the VIBRC
register to save power.
V IB
V ib r a tio n
S e n s o r
A m p lifie r
C ir c u its
M C U w a k e -u p
V IB R E N
VIBRC Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
—
VIBREN
R/W
—
—
—
—
—
—
—
R/W
POR
—
—
—
—
—
—
—
0
Bit 7~1 Unimplemented, read as “0”
Bit 0 VIBREN: Vibration Sensor Amplifier control
0: disabled
1: enabled
Touch Key Module
The device contains four touch keys. The touch key functions are fully integrated and require no
external components, allowing touch key functions to be implemented by the simple manipulation
of internal registers.
Touch Key Structure
The touch keys are pin shared with the PB logic I/O pins, with the desired function chosen via
register bits.
Touch Key Register Definition
The touch key functions have their own suite of registers. The following table shows the register set
together with a basic description.
Name
Usage
TKM016DH
16-bit C/F counter high byte
TKM016DL
16-bit C/F counter low byte
TKM010DL
10-bit counter low byte
TKM0RO
Internal Capacitor Select
TKM0C0
Control Register 0 Key Select/X2 freq/filter control/frequency select
TKM0C1
Control Register 1 Sensor Oscillator Control/Touch key or I/O select.
TKM0C2
Control Register 2 Counter on-off and clear control/reference clock control/Start bit
TKM0C3
Control Register 3 Counter overflow bits/Reference Oscillator Overflow Time Select
TKM0C4
Control Register 4 fVDD Clock Source Select/Power control
Register Listing
Rev. 1.20
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Register
Name
Bits
7
6
5
4
3
TKM016DH
D7
D6
TKMn16DL
D7
D6
TKM010DL
D7
D6
D5
2
1
D5
D4
D5
D4
D4
0
D3
D2
D1
D0
D3
D2
D1
D0
D3
D2
D1
D0
TKM0RO
D7
D6
D5
D4
D3
D2
D1
D0
TKM0C0
M0MXS1
M0MXS0
M0DFEN
M0FILEN
M0SOFC
M0SOF2
M0SOF1
M0SOF0
TKM0C1
M0K4OEN
M0K3OEN
M0K2OEN
M0K1OEN
M0K4IO
M0K3IO
M0K2IO
M0K1IO
TKM0C2
M016CTON M010CTON
M0ST
M0ROEN
TKM0C3
D9
D8
M0RCOV
TKM0C4
—
FVDD2
FVDD1
M0RCCLR M016CTCLR M010CTCLR
M016CTOV M010CTOV
FVDD0
—
M0ROS
M0ROVS2
M0ROVS1
M0ROVS0
—
—
NORM
Register Content Summary
TKM016DH Register
Bit
7
6
5
4
3
2
1
0
Name
D15
D14
D13
D12
D11
D10
D9
D8
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
Bit 7~0 D15~D8: Touch key module 16-bit counter (TMCNT) high byte.
TKM016DL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
Bit 7~0 D7~D0: Touch key module 16-bit counter (TMCNT) low byte.
TKM010DL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
1
0
Bit 7~0 D7~D0: touch key module 10-bit counter (TMCNT) bit 7~ bit 0.
TKM0RO Register
Bit
6
5
4
3
2
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
1
Bit 7~0
Rev. 1.20
7
D7~D0: Integrated OSC capacitor can select TKMORCC[7:0]×50pF/256. It is not
permitted to write a 00H value to this register.
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
TKM0C0 Register
Bit
Name
Rev. 1.20
7
6
5
4
3
2
M0MXS1 M0MXS0 M0DFEN M0FILEN M0SOFC M0SOF2
1
0
M0SOF1
M0SOF0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~6 M0MXS1~M0MXS0: multiplexer key select.
00: KEY 1
01: KEY 2
10: KEY 3
11: KEY 4
Bit 5 M0DFEN: double frequency function control
0: disable
1: enable
Bit 4 M0FILEN: filter function control
0: disable
1: enable
Bit 3 M0SOFC: C to F OSC frequency hopping function select
0: frequency hopping is controlled by software and C to F OSC micro adjustment
frequency is determined by the M0SOF2~M0SOF0 bits
1: frequency hopping controlled by hardware - M0SOF2~M0SOF0 bits have no effect.
Here the counter’s three MSBs, selected by M0ROVS2~M0ROVS0, will automatically
adjust the C to F OSC micro adjustment frequency.
Bit 2~0 M0SOF2~ M0SOF0: C to F OSC frequency hopping frequency select
000: 400 kHz
001: 425 kHz
010: 450 kHz
011: 475 kHz
100: 500 kHz
101: 525 kHz
110: 550 kHz
111: 575 kHz
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
TKM0C1 Register
Bit
Name
Rev. 1.20
7
6
5
4
3
M0K4OEN M0K3OEN M0K2OEN M0K1OEN M0K4IO
2
1
0
M0K3IO
M0K2IO
M0K1IO
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 M0K4OEN: KEY 4 Sensor Oscillator Control
0: disable
1: enable
Bit 6 M0K3OEN: KEY 3 Sensor Oscillator Control
0: disable
1: enable
Bit 5 M0K2OEN: KEY 2 Sensor Oscillator Control
0: disable
1: enable
Bit 4 M0K1OEN: KEY 1 Sensor Oscillator Control
0: disable
1: enable
Bit 3 M0K4IO: KEY 4 touch key input or I/O function
0: I/O
1: Touch key input
Bit 2 M0K3IO: KEY 3 touch key input or I/O function
0: I/O
1: Touch key input
Bit 1 M0K2IO: KEY 2 touch key input or I/O function
0: I/O
1: Touch key input
Bit 0 M0K1IO: KEY 1 touch key input or I/O function
0: I/O
1: Touch key input
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
TKM0C2 Register
Bit
Name
Rev. 1.20
7
6
M016CTON M010CTON
5
4
M0ST
M0ROEN
3
2
1
0
M0RCCLR M016CTCLR M010CTCLR
M0ROS
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 M016CTON: 16-bit C/F Counter Control
0: disable
1: enable
This bit is cleared by hardware when the M0RCOV bit is set to 1.
Bit 6 M010CTON: 10-bit Counter Control
0: disable
1: enable
This bit is cleared by hardware when the M0RCOV bit is set to 1.
Bit 5 M0ST: Start fTMCK and fVDDCK output clock
0: Hardware sets ENCK to low, reference oscillator 13-stage counter stops
0→1: Enable the fTMCK and fVDDCK output clock - hardware sets ENCK to high.
Hardware sets clears the M0RCOV flag low and the Reference Oscillator 13-stage
counter start counting. If the counter overflows, the M0RCOV flag is set to “1”, the
hardware clears ENCK to low and the Touch Key Interrupt request flag, TKF, will be
set. A Touch Key Interrupt will be generated if the Touch Key Interrupt enable bit,
TKE, and the Global Interrupt bit, EMI, are set to 1.
Bit 4 M0ROEN: Reference Clock Control
0: disable
1: enable
Bit 3 M0RCCLR: Clear Reference Oscillator 13-stage counter
0: no change
1: clear counter
The hardware circuit will clear this bit to zero after it is set to “1” by the user.
Bit 2 M016CTCLR: 16-bit C/F Counter Clear Control
0: no change
1: clear counter
Hardware will clear this bit to zero after it is set to “1” by user.
Bit 1 M010CTCLR: 10-bit counter Clear Control
0: no change
1: clear counter
Hardware will clear this bit to zero after it is set to “1” by user.
Bit 0 M0ROS: Reference Oscillator 13-stage Counter Clock Source Select
0: Reference OSC
1: KEY 4 Sensor OSC
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
TKM0C3 Register
Bit
7
6
Name
D9
D8
5
4
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
M0RCOV M016CTOV M010CTOV M0ROVS2 M0ROVS1 M0ROVS0
Bit 7~6 D9~ D8: fVDD 10-bit Counter Bit 9 and Bit 8
Bit 5 M0RCOV: 13-stage Counter Overflow Flag
0: no overflow
1: overflow
If the 13-stage counter overflows, the Touch Key Interrupt request flag, TKF, will be
set and the hardware will clear ENCK to low to disable the fTMCK and fVDDCK
outputs.
Bit 4 M016CTOV: 16-bit C/F Counter Overflow Flag
0: no overflow
1: overflow
This bit must be cleared by software.
Bit 3 M010CTOV: 10-bit Counter Overflow Flag
0: no overflow
1: overflow
This bit must be cleared by software.
Bit 2~0 M0ROVS2~ M0ROVS0: Reference Oscillator 13-stage Counter Overflow Time Select
Switch 0 control bits:
000: 64 counts
001: 128 counts
010: 256 counts
011: 512 counts
100: 1024 counts
101: 2048 counts
110: 4096 counts
111: 8192 counts
TKM0C4 Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
—
FVDD2
FVDD1
FVDD0
—
—
—
NORM
R/W
—
R/W
R/W
R/W
—
—
—
R/W
POR
—
0
0
0
—
—
—
0
Bit 7 Unimplemented, read as “0”
Bit 6~4 FVDD2~ FVDD0: FVDD Clock Source Select
000: fSYS/2
001: fSYS/4
010: fSYS/8
011: fSYS/16
100: fSYS/32
101: fSYS/64
110: fSYS/128
111: fSUB
Bit 3~1 Unimplemented, read as “0”
Bit 0 NORM: Normal/Low Power Mode Select
0: Low power mode
1: Normal mode
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Touch Key Operation
When a finger touches or is in proximity to a touch pad, the capacitance of the pad will increase.
By using this capacitance variation to change slightly the frequency of the internal sense oscillator,
touch actions can be sensed by measuring these frequency changes. Using an internal programmable
divider the reference clock is used to generate a fixed time period. By counting a number of
generated clock cycles from the sense oscillator during this fixed time period touch key actions can
be determined.
The device contains four touch key inputs which are shared with logical I/O pins, with the desired
function selected using register bits. The Touch Key module also has its own interrupt vectors and
set of interrupts flags.
During this reference clock fixed interval, the number of clock cycles generated by the sense
oscillator is measured, and it is this value that is used to determine if a touch action has been made
or not. At the end of the fixed reference clock time interval, a Touch Key interrupt signal will be
generated.
Touch Switch Module Block Diagram
Touch Key or I/O Function Select
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Touch Key Interrupts
The touch key module, which consists of four touch keys, has three independent interrupts,
an overall touch key interrupt as well as one for the 16-bit C/F counter and one for the 10bit counter. The 16-bit C/F counter and 10-bit counter interrupts are contained within the
Multi-function interrupts and therefore do not have their own vectors. Care must be taken
during programming as these counter interrupt flags contained within the Multi-function
interrupts will not be automatically reset upon entry into the interrupt service routine but
rather must be reset manually by the application program. More details regarding the
touch key interrupts are located in the interrupt section of the datasheet.
Programming Considerations
After the relevant registers are setup, the touch key detection process is initiated the changing the
M0ST bit from low to high. This will enable and synchronise all relevant oscillators.
Charge Pump and Voltage Regulator
One charge pump and one voltage regulator are implemented in this device as way of providing a
stable voltage source for certain internal functions. An additional Bandgap voltage source is also
provided.
Operation
The charge pump can be enabled or disabled by the application program. The charge pump uses
VDD as its input, and has the function of doubling the VDD voltage. The output voltage of the
charge pump will be VDD×2. The regulator can generate a stable voltage of 3.3V, which is used
by the internal WDT and A/D Converter and can also provide an external bridge sensor excitation
voltage or supply a reference voltage for other applications. The user needs to guarantee that the
charge pump output voltage is greater than 3.6V to ensure that the regulator generates the required
3.3V voltage output. The block diagram of this module is shown below.
CHPC 2
VDD
CHPC1
Charge Pump
(Voltage Doubler)
fs
VOREG
VOCHP
VDD
VDD ∃ 2
Regulator
(�.�V)
�.�V
OP
ADC
Divider
CHPCKD
REGEN
CHPEN
Charge Pump and Regulator Block Diagram
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Additionally, the device also includes a band gap voltage generator for the 1.5V low temperature
sensitive reference voltage. This reference voltage is used as the zero adjustment and for a single
end type reference voltage.

RFIL is about 100KΩ and the recommend CFIL is 10μF.
Note: The VOBGP signal is only for internal used. It must not be connected to external components except
for the recommend CFIL capacitor.
There is a single register associated with this module named CHPRC. The CHPRC is the Charge
Pump/Regulator Control register, which controls the charge pump on/off, regulator on/off functions
as well as a clock divider value to generate the charge pump clock. The CHPCKD4~CHPCKD0
bits are use to set the clock divider to generate the desired clock frequency for proper charge pump
operation. The actual frequency is determined by the following formula.
Actual Charge Pump Clock= (fSYS/16) / (CHPCKD +1).
CHPRC Register
Bit
Name
Rev. 1.20
7
6
5
4
3
2
CHPCKD4 CHPCKD3 CHPCKD2 CHPCKD1 CHPCKD0 BGPQST
1
0
CHPEN
REGEN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~3 CHPCKD4~CHPCKD0: The Charge pump clock divider
These 5 bits select the clock divider ration of 1~32.
Charge Pump clock = (fSYS/16) / (CHPCKD+1)
Bit 2 BGPQST: Bandgap quick start-up function
0: R short, quickly start
1: R connected, normal RC filter mode
Every time when REGEN changes from 0 to 1 (regulator turns on), this bit should be
set to 0 and then set to 1 to make sure the Bandgap stabilises quickly (The minimum
time is about 2ms now).
Bit 1
CHPEN: Charge Pump on/off control
0: disable
1: enable
Note: this bit will be ignored if the REGEN is disabled.
Bit 0 REGEN: Regulator/Charge-Pump module on/off control
0: disable
1: enable
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
REGEN CHPEN
Charge VOCHP
Regulator
Pump
Pin
VOREG
Pin
OPA, ADC
Body Fat Circuit
Description
Whole module is disabled, OPA/
ADC/body fat circuit will lose power
0
×
OFF
VDD
OFF
HiImpedance
Disable
1
0
OFF
VDD
ON
3.3V
Active
Used when VDD is greater than
3.6V (VDD> 3.6V)
1
1
ON
2×VDD
ON
3.3V
Active
Use when VDD is less than 3.6V
(VDD= 2.2V - 3.6V)
The suggested charge pump clock frequency is 20kHz. The application needs to set the correct value
to get the desired clock frequency. For a 4MHz application, the CHPCKD bits should be set to the
value 11, and for a 2MHz application, the bits should be set to 5.
The REGEN bit in the CHPRC register is the Regulator/Charge-pump module enable/disable control
bit. If this bit is disabled, then the regulator will be disabled and the charge pump will be also be
disabled to save power. When REGEN= 0, the module will enter the power down mode ignoring the
CHPEN setting. The A/D Converter and OPA will also be disabled to reduce power.
If REGEN is set to “1”, the regulator will be enabled. If CHPEN is enabled, the charge pump will be
active and will use VDD as its input to generate the double voltage output. This double voltage will
be used as the input voltage for the regulator. If CHPEN is set to “0”, the charge pump is disabled
and the charge pump output will be equal to the charge pump input VDD.
It is necessary to take care of the VDD voltage. If the voltage is less than 3.6V, then CHPEN should
be set to 1 to enable the charge pump, otherwise CHPEN should be set to zero. If the Charge pump
is disabled and VDD is less than 3.6V then the output voltage of the regulator will not be guaranteed.
Dual Slope A/D Converter
A Dual Slope A/D converter is implemented in the device. The dual slope module includes an
Instrumentation Amplifier, a Programmable Gain Amplifier, for the amplification of differential
signals, an Integrator and a comparator for the main dual slope AD convertor.
There are two special function registers related to this function known as ADCR and ADCD. The
ADCR register is the A/D control register, which controls the ADC block power on/off, the chopper
clock on/off, the charge/discharge control and is also used to read out the comparator output status.
The ADCD register is the A/D Chopper clock divider register, which defines the chopper clock to
the ADC module.
The ADPWREN bit, defined in ADCR register, is used to control the ADC module on/off function.
The ADCCKEN bit, defined in the ADCR register, is used to control the chopper clock on/off
function. When ADCCKEN is set to “1” it will enable the Chopper clock, with the clock frequency
defined by the ADCD register. The ADC module includes the OPA, PGA, integrator and comparator.
However, the Bandgap voltage generator is independent of this module. It will be automatically
enabled when the regulator is enabled, and also be disabled when the regulator is disabled. The
application program should enable the related power to permit them to function and disable
them when entering the power down mode to conserve power. The charge/discharge control bits,
ADDISCH1 and ADDISCH0, are used to control the Dual slope circuit charging and discharging
behavior. The ADCMPO bit is read only for the comparator output, while the ADINTM bits can set
the ADCMPO trigger mode for interrupt generation. The ADC PGA input signal can come from
the DCHOP or TH/LB pin selected by the ADIS selection bit in ADCD register. The PGA gain can
be either 2 or 4 determined by the PGAG gain selection bit in the ADCD register. The reference
voltages of the ADC integrator and comparator named VINT and VCMP shown in the Dual Slope
ADC structure diagram can be selected by the ADRR0 selection bit.
Rev. 1.20
65
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale

Dual Slope ADC Structure
An instrumentation amplifier is included to provide a high CMRR amplifying interface to differential
signals from external sensors. With a standard instrumentation amplifier setup of three operational
amplifiers and a DAC for offset calibration, this structure provides a low noise sensor interface.
Two registers are used for overall control of the instrumentation amplifier and a single register for
DAC control. If these functions are not used they should be disabled using the register bits to reduce
power consumption.
DOPAN
+
102
-
0.22uF
OP5N
OP3
100pF
10k
RA_String
47uF
16V
Bridge
Sensor
0.1uF
RSEN
Gain = 1/2/4/8/16/32
+
82k
OP5
DOPAO
Gain = 4/5/6/7/8/9
+
102
10k
OP4
DCHOP
Vout
105
RB_String
OP5P
DOPAP
RSEN
100pF
6 bits
DAC
Instrumentation Amplifier
Rev. 1.20
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Dual Slope Anolog Digital Convertor Operation
The following descriptions are based on the fact that the ADRR0 bit is set to “0”. The
instrumentation amplifier and PGA combination, form a differential input pre-amplifier which
amplifies the sensor input signal. The combination of the Integrator, the comparator, the resistor
Rds, between DSRR and DSRC and the capacitor Cds, between DSRC and DSCC, form the main
body of the Dual slope ADC. The Integrator integrates the output voltage increase or decrease and
is controlled by the “Switch Circuit” - refer to the block diagram. The integration and de-integration
curves are illustrated by the following.
The “comparator” will switch the state from high to low when VC, which is the DSCC pin voltage,
drops to less than 1/6 VDSO.
In general applications, the application program will switch the ADC to the charging mode for a
fixed time called Ti, which is the integrating time. It will then switch to the discharging mode and
wait for Vc to drop to less than 1/6 VDSO. At this point the comparator will change state and store
the time taken, TC, which is the de-integrating time. The following formula 1 can then be used to
calculate the input voltage VA.
formula 1: VA= (1/3) × VDSO × (2 - TC/Ti).
(Based on ADRR0=0)
In user applications, it is required to choose the correct value of Rds and Cds to determine the Ti
value, to allow the VC value to operate between 5/6 VDSO and 1/6 VDSO. VFULL cannot be greater
than 5/6 VDSO and VZERO cannot be less than 1/6 VDSO.
Rev. 1.20
67
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
ADCR Register
Bit
7
Name
—
6
5
4
3
2
1
0
R/W
—
R/W
R/W
R/W
R
R/W
R/W
R/W
POR
—
0
0
0
×
0
0
0
ADCCKEN ADINTM1 ADINTM0 ADCMPO ADDISCH1 ADDISCH0 ADPWREN
“×” unknown
Bit 7
Unimplemented, read as “0”
Bit 6
ADCCKEN: A/D Convertor OP chopper clock source on/off switching
0: disable
1: enable (clock value is defined by ADCD register)
Bit 5~4
ADINTM1, ADINTM0: ADCMPO data interrupt trigger mode definition
00: no interrupt
01: rising edge
10: falling edge
11: both edges
Bit 3
ADCMPO: Dual Slope ADC - last stage comparator output. Read only bit, write data
instructions will be ignored. During the discharging state, when the integrator output is less
than the reference voltage,the ADCMPO will change from high to low.
Bit 2~1 ADDISCH1~ ADDISCH0: ADC discharge/charge definition
00: reserved
01: charging (Integrator input connect to buffer output)
10: discharging (Integrator input connect to VDSO)
11: reserved
Bit 0 ADPWREN: Dual slope block (including input OP) power on/off switching
0: disable Power
1: Power source comes from the regulator
ADCD Register
Bit
7
6
5
4
3
2
1
0
Name
PGAG
ADIS1
ADIS0
ADRR0
—
ADCD2
ADCD1
ADCD0
R/W
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
POR
0
0
0
0
—
1
1
1
Bit 7
PGAG: PGA gain selection
Bit 6~5 0: gain = 2
1: gain = 4
ADIS1~ADIS0: A/D PGA input selection
00: from RFC pin
01: from TH/LB pin
10: from DCHOP pin
11: reserved
ADRR0: A/D integrator and comparator reference voltage selection
Bit 4 0: (VINT, VCMP) = (4/6 VDSO, 1/6 VDSO)
1: (VINT, VCMP) = (4.4/6 VDSO, 1/6 VDSO)
Bit 3
Rev. 1.20
Unimplemented, read as “0”
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May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Bit 2~0
ADCD2~ADCD0: Chopper clock definition (ADCCKEN should be enable), the
suggestion clock is around 10kHz
000: (fSYS/32)/1
001: (fSYS/32)/2
010: (fSYS/32)/4
011: (fSYS/32)/8
100: (fSYS/32)/16
101: (fSYS/32)/32
110: (fSYS/32)/64
111: (fSYS/32)/128
IAC0 Register
Bit
7
6
5
4
3
2
1
0
Name
IAEN
G12
G11
G10
IA2EN
G02
G01
G00
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
bit 7
IAEN: OP3, OP4 on/off control
0: off
1: on
bit 6 ~ 4
G12~G10: Instrumentation Amplifier 2nd Stage Gain
000: 4
001: 5
010: 6
011: 7
100: 8
1xx: 9
bit 3
IA2EN: OP5 on/off control.
0: off
1: on
bit 2 ~ 0
G02~G00: Instrumentation Amplifier 1st Stage Gain
000: 1
001: 2
010: 4
011: 8
100: 16
1xx: 32
IAC1 Register
Bit
Name
7
6
5
CHOPEN BI_PGA1 BI_PGA0
4
3
2
1
0
IAD2
IAD1
IAD0
—
RSEN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
—
R/W
POR
1
1
1
1
0
0
0
1
'x' unknown
Rev. 1.20
bit 7
CHOPEN: OP3, OP4 Chopper Enable
0: disable
1: enable
bit 6 ~ 5
BI_PGA1~BI_PGA0: OP3 and OP4 Operating Current Selection
00: I
01: 3I
10: 5I
11: 7I (op3 and op4 current=400µA, IA (op3, op4, op5) current=1.2mA)
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IAD2~IAD1: Chopper Clock Select
IA chopper clock defined as:
000: clock= (fSYS/32)/1
001: clock= (fSYS/32)/2
010: clock= (fSYS/32)/4
011: clock= (fSYS/32)/8
100: clock= (fSYS/32)/16
101: clock= (fSYS/32)/32
110: clock= (fSYS/32)/64
111: clock= (fSYS/32)/128
A suggested clock speed has a range of around 8-10kHz. Note that CHOPEN must be
enabled – here the IA chopper clock is approximate 8k ~10k.(7.8125k ~ 11.71875k)
and the ADC chopper clock must be < 8k.
bit 4 ~ 2
bit 1
Unimplemented, read as "0"
bit 0
RSEN: OP5 external/internal gain setup control bit
0: Open loop setup – gain defined by external reisistors.
1: Closed loop setup – gain defined by G10, G11 and G12 bits in the IAC0 register.
IADAC Register
Bit
7
6
5
4
3
2
1
0
Name
IADAEN
—
D5
D4
D3
D2
D1
D0
R/W
R/W
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
IADAEN: IA DAC enable/disable
0: disable
1: enable
bit 7
bit 6
Unimplemented, read as "0"
bit 5 ~ 0
D5~D0: DAC Output Voltage Setup Bits
Note: The DAC output range is 0V ~ {VOREG-(VOREG/64)}
1 LSB = 1 digital code = VOREG/64
Output Voltage= VOREG/64*(D[5:0])
Interrupts
Interrupts are an important part of any microcontroller system. When an external event or an internal
function such as a Timer/Event Counter or an A/D converter requires microcontroller attention,
their corresponding interrupt will enforce a temporary suspension of the main program allowing the
microcontroller to direct attention to their respective needs.
The device provides an external interrupt and multiple internal interrupts. The external interrupt is
controlled by the action of the external interrupt pin, while the internal interrupts are controlled by
the Timer/Event Counters, Touch Key and A/D converter.
Interrupt Register
Overall interrupt control, which means interrupt enabling and request flag setting, is controlled by
using three registers, INTC0, INTC1 and MFIC. By controlling the appropriate enable bits in this
registers each individual interrupt can be enabled or disabled. Also when an interrupt occurs, the
corresponding request flag will be set by the microcontroller. The global enable flag if cleared to
zero will disable all interrupts.
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INTC0 Register
Bit
7
6
5
4
3
2
1
0
Name
—
T1F
T0F
EIF
ET1I
ET0I
EEI
EMI
R/W
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
0
0
0
0
0
0
0
Bit 7
unimplemented, read as “0”
Bit 6
T1F: Timer/Event Counter 1 interrupt request flag
0: inactive
1: active
Bit 5
T0F: Timer/Event Counter 0 interrupt request flag
0: inactive
1: active
Bit 4
EIF: External interrupt request flag
0: inactive
1: active
Bit 3
ET1I: Timer/Event Counter 1 interrupt enable
0: disable
1: enable
Bit 2
ET0I: Timer/Event Counter 0 interrupt enable
0: disable
1: enable
Bit 1
EEI: External interrupt enable
0: disable
1: enable
Bit 0
EMI: Master interrupt global enable
0: disable
1: enable
INTC1 Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
—
TKF
ADF
MFF
—
TKE
EADI
EMFI
R/W
—
R/W
R/W
R/W
—
R/W
R/W
R/W
POR
—
0
0
0
—
0
0
0
Bit 7
unimplemented, read as “0”
Bit 6
TKF: Touch key interrupt request flag
0: inactive
1: active
Bit 5
ADF: A/D Convertor request flag
0: inactive
1: active
Bit 4
MFF: Multi-function interrupt request flag
0: inactive
1: active
Bit 3
unimplemented, read as “0”
Bit 2
TKE: Touch key interrupt enable
0: disable
1: enable
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Bit 1
EADI: A/D Convertor interrupt enable
0: disable
1: enable
Bit 0
EMFI: Multi-function interrupt enable
0: disable
1: enable
MFIC Register
Bit
7
6
5
4
3
2
1
0
Name
—
M16CTF
R/W
—
R/W
M10CTF
T2F
—
M16CTE
M10CTE
ET2I
R/W
R/W
—
R/W
R/W
R/W
POR
—
0
0
0
—
0
0
0
Bit 7 unimplemented, read as “0”
Bit 6 M16CTF: Touch Key Module 16-bit Counter interrupt request flag
0: inactive
1: active
Bit 5
M10CTF: Touch Key Module 10-bit Counter interrupt request flag
0: inactive
1: active
Bit 4
T2F: Timer/Event Counter 2 interrupt request flag
0: inactive
1: active
Bit 3
unimplemented, read as “0”
Bit 2
M16CTE: Touch Key Module 16-bit Counter interrupt enable
0: disable
1: enable
Bit 1
M10CTE: Touch Key Module 10-bit Counter interrupt enable
0: disable
1: enable
Bit 0
ET2I: Timer/Event Counter 2 interrupt enable
0: disable
1: enable
Interrupt Operation
A Timer/Event or Touch Key Counter overflow, an active edge on the external interrupt pin, A/D
conversion completion, or a signal completion of the Touch Key sensor will all generate an interrupt
request by setting their corresponding request flag, if their appropriate interrupt enable bit is set.
When this happens, the Program Counter, which stores the address of the next instruction to be
executed, will be transferred onto the stack. The Program Counter will then be loaded with a new
address which will be the value of the corresponding interrupt vector. The microcontroller will
then fetch its next instruction from this interrupt vector. The instruction at this vector will usually
be a JMP statement which will jump to another section of program which is known as the interrupt
service routine. Here is located the code to control the appropriate interrupt. The interrupt service
routine must be terminated with a RETI instruction, which retrieves the original Program Counter
address from the stack and allows the microcontroller to continue with normal execution at the point
where the interrupt occurred.
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The various interrupt enable bits, together with their associated request flags, are shown in the
following diagram with their order of priority.
EMI auto disabled in ISR
Interrupt
Vector
xxF
Request Flag – no auto reset in ISR
Interrupt
Name
xxF
Request Flag – auto reset in ISR
INT Pin
EIF
EEI
EMI
04H
xxE
Enable Bit
Timer0
T0F
ET0I
EMI
08H
Timer1
T1F
ET1I
EMI
0CH
MFF
EMFI
EMI
10H
A/D
ADF
EADI
EMI
14H
Touch Key
TKF
TKE
EMI
18H
Interrupt
Name
Request
Flags
Enable
Bits
TK 16-bit
M16CTF
M16CTE
TK 10-bit
M10CTF
M10CTE
Timer2
T2F
ET21
Multi-Function
Request
Flags
Enable
Bits
Master
Enable
Priority
High
Low
Interrupts contained within Multi-Function Interrupt
Interrupt Structure
Once an interrupt subroutine is serviced, all the other interrupts will be blocked, as the EMI bit will
be cleared automatically. This will prevent any further interrupt nesting from occurring. However,
if other interrupt requests occur during this interval, although the interrupt will not be immediately
serviced, the request flag will still be recorded. If an interrupt requires immediate servicing while the
program is already in another interrupt service routine, the EMI bit should be set after entering the
routine, to allow interrupt nesting. If the stack is full, the interrupt request will not be acknowledged,
even if the related interrupt is enabled, until the Stack Pointer is decremented. If immediate service
is desired, the stack must be prevented from becoming full.
When an interrupt request is generated it takes 2 or 3 instruction cycle before the program jumps
to the interrupt vector. If the device is in the Sleep or Idle Mode and is woken up by an interrupt
request then it will take 3 cycles before the program jumps to the interrupt vector.
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�ain
Program
Interrupt Request or
Interrupt Flag Set b� Instruction
N
Enable bit set?
Y
Automaticall� Disable Interrupt
Clear E�I & Request Flag
�ain
Program
Wait for 2~� Instruction C�cles
ISR Entr�
...
...
RETI
(it will set E�I automaticall�)
Interrupt Flow
Interrupt Priority
Interrupts, occurring in the interval between the rising edges of two consecutive T2 pulses, will be
serviced on the latter of the two T2 pulses, if the corresponding interrupts are enabled. In case of
simultaneous requests, the following table shows the priority that is applied. These can be masked
by resetting the EMI bit.
Interrupt Source
Priority
Vector
External Interrupt 0
1
04H
Timer/Event Counter 0 Overflow
2
08H
Timer/Event Counter 1 Overflow
3
0CH
Multi Function Interrupt (Timer/Event Counter overflow 2 and
Touch Key Module 10-bit/16-bit counter overflow)
4
10H
A/D Convertor Interrupt
5
14H
Touch Key Interrupt
6
18H
Interrupt Subroutine Vector
In cases where both external and internal interrupts are enabled and where an external and internal
interrupt occurs simultaneously, the external interrupt will always have priority and will therefore be
serviced first. Suitable masking of the individual interrupts using the interrupt registers can prevent
simultaneous occurrences.
External Interrupt
For an external interrupt to occur, the global interrupt enable bit, EMI, and external interrupt enable
bit, EEI, must first be set. An actual external interrupt will take place when the external interrupt
request flag, EIF, is set, a situation that will occur when an edge transition appears on the external
INT line. The type of transition that will trigger an external interrupt, whether high to low, low to
high or both is determined by the EINTC0 and EINTC1 bits, which are bits 6 and 7 respectively, in
the CTRL1 control register. These two bits can also disable the external interrupt function.
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EINTC1
EINTC0
0
0
Disable
Edge Trigger Type
0
1
Falling edge trigger
1
0
Rising edge trigger
1
1
Dual edge trigger
The external interrupt pin is pin-shared with the I/O pin PB4 and can only be configured as an
external interrupt pin if the corresponding external interrupt enable bit in the INTC0 register has
been set and the edge trigger type has been selected using the CTRL1 register. The pin must also
be setup as an input by setting the corresponding PBC.4 bit in the port control register. When the
interrupt is enabled, the stack is not full and an active transition appears on the external interrupt pin,
a subroutine call to the external interrupt vector at location 04H, will take place. When the interrupt
is serviced, the external interrupt request flag, EIF, will be automatically reset and the EMI bit will
be automatically cleared to disable other interrupts. Note that any pull-high resistor connections on
this pin will remain valid even if the pin is used as an external interrupt input.
Timer/Event Counter Interrupt
For a Timer/Event Counter interrupt to occur, the global interrupt enable bit, EMI, and the
corresponding timer interrupt enable bit, ETnI, must first be set. An actual Timer/Event Counter
interrupt will take place when the Timer/Event Counter request flag, TnF, is set, a situation that will
occur when the relevant Timer/Event Counter overflows. When the interrupt is enabled, the stack
is not full and a Timer/Event Counter n overflow occurs, a subroutine call to the relevant timer
interrupt vector, will take place. When the interrupt is serviced, the timer interrupt request flag, TnF,
will be automatically reset and the EMI bit will be automatically cleared to disable other interrupts.
Multi-function Interrupt
The device has one Multi-function interrupt. Unlike the other independent interrupts, this interrupt
have no independent source, but rather are formed from other existing interrupt sources, namely
Touch Key 16-bit Counter Interrupt, Touch Key 10-bit Counter Interrupt and Timer/Event Counter 2
Interrupt.
A Multi-function interrupt request will take place when any of the Multi-function interrupt request
flag MFF is set. The Multi-function interrupt flag will be set when any of its included functions
generate an interrupt request flag. To allow the program to branch to its respective interrupt vector
address, when the Multi-function interrupt is enabled and the stack is not full, and either one of the
interrupts contained within Multi-function interrupt will occur, a subroutine call to one of the Multifunction interrupt vectors will take place. When the interrupt is serviced, the related Multi-Function
request flag will be automatically reset and the EMI bit will be automatically cleared to disable other
interrupts.
However, it must be noted that, although the Multi-function Interrupt flag will be automatically
reset when the interrupt is serviced, the request flag from the original source of the Multi-function
interrupt, namely Touch Key 16-bit Counter Interrupt, Touch Key 10-bit Counter Interrupt and
Timer/Event Counter 2 Interrupt will not be automatically reset and must be manually reset by the
application program.
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A/D Converter Interrupt
The A/D Converter interrupt is initialized by setting the A/D converter request flag, caused by an
end of A/D conversion. When the interrupt is enabled, the stack is not full and the ADF is set, a subroutine call will occur. The related interrupt request flag ADF will be reset and the EMI bit cleared
to disable further interrupts.
Touch Key Interrupt
The Touch Key interrupt is initialized by setting the Touch Key interrupt request flag, TKF, bit 6
of INTC1. This is caused by a signal completion of the Touch Key sensor. After the interrupt is
enabled, and the stack is not full, and the TKF bit is set, a sub-routine call will occur. The related
interrupt request flag TKF, will be reset and the EMI bit is cleared to disable further interrupts.
Programming Considerations
By disabling the relevant interrupt enable bits, a requested interrupt can be prevented from being
serviced, however, once an interrupt request flag is set, it will remain in this condition in the
interrupt register until the corresponding interrupt is serviced or until the request flag is cleared by
the application program. It is recommended that programs do not use the CALL instruction within
the interrupt service subroutine. Interrupts often occur in an unpredictable manner or need to be
serviced immediately. If only one stack is left and the interrupt is not well controlled, the original
control sequence will be damaged once a CALL subroutine is executed in the interrupt subroutine.
Every interrupt has the capability of waking up the microcontroller when it is Power down Mode,
the wake up being generated when the interrupt request flag changes from low to high. If it is
required to prevent a certain interrupt from waking up the microcontroller then its respective request
flag should be first set high before entering the Power down Mode.
As only the Program Counter is pushed onto the stack, then when the interrupt is serviced, if the
contents of the accumulator, status register or other registers are altered by the interrupt service
program, their contents should be saved to the memory at the beginning of the interrupt service
routine.
To return from an interrupt subroutine, either a RET or RETI instruction may be executed. The RETI
instruction in addition to executing a return to the main program also automatically sets the EMI
bit high to allow further interrupts. The RET instruction however only executes a return to the main
program leaving the EMI bit in its present zero state and therefore disabling the execution of further
interrupts.
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LCD Driver
For large volume applications, which incorporate an LCD in their design, the use of a custom
display rather than a more expensive character based display reduces costs significantly. However,
the corresponding signals required, which vary in both amplitude and time, to drive such a custom
display require many special considerations for proper LCD operation to occur. The Holtek
LCD Driver function, with its internal LCD signal generating circuitry and various options, will
automatically generate these time and amplitude varying signals to provide a means of direct driving
and easy interfacing to a range of custom LCDs.
LCD Memory
An area of Data Memory is especially reserved for use by the LCD data. This data area
is known as the LCD Memory. Any data written here will be automatically read by the
internal LCD driver circuits, which will in turn automatically generate the necessary LCD
driving signals. Therefore any data written into the LCD Memory will be immediately
reflected into the actual LCD display connected to the microcontroller. The start address of
the LCD Memory is 40H; the end address of the LCD Memory is 5BH.
As the LCD Data Memory addresses overlap those of the General Purpose Data Memory,
the LCD Data Memory is stored in its own memory data bank, which is different from
that of the General Purpose Data Memory. The LCD Data Memory is stored in Bank 1.
The Data Memory Bank is chosen by using the Bank Pointer, which is a special function
register in the Data Memory, with the name, BP. When the lowest bit of the Bank Pointer
has the binary value “0”, only the General Purpose Data Memory will be accessed, no
read or write actions to the LCD Memory will take place. To access the LCD Memory
therefore requires first that Bank 1 is selected by setting the lowest bit of the Bank Pointer
to the binary value “1”. After this, the LCD Memory can then be accessed by using
indirect addressing through the use of Memory Pointer MP1. With Bank 1 selected, then
using MP1 to read or write to the memory area 40H~5BH, will result in operations to the
LCD Memory. Directly addressing the LCD Memory is not applicable and will result in a
data access to the Bank 0 General Purpose Data Memory.
LCD Memory Map
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LCD Registers
A single LCD Control Registers in the Data Memory, known as LCDC, is used to control the various
setup features of the LCD Driver. Various bits in this register control functions such as VA voltage,
bias type, duty type as well as LCD COM/SEG selection.
LCDC Register
Bit
7
Name
R/W
POR
Bit 7
6
5
4
3
2
1
0
LCDPD
VAS
—
R/W
R/W
—
RCS
—
CSS2
CSS1
CSS0
R/W
R/W
R/W
R/W
R/W
0
0
—
0
—
0
0
0
LCDPD: LCD on/off control
0: LCD enable
1: LCD disable
VAS: VA voltage selection for C type LCD
Bit 6 0: VOREG
1: 1.5×VOREG
Bit 5 Unimplemented, read as “0”
Bit 4 RCS: LCD type R or C
0: R type
1: C type
Bit 3
Unimplemented, read as “0”
CSS2~CSS0: LCD COM[7:4]/SEG[27:24] selection, Refer to the following table for
details
Note: When the charge pump output voltage is equal to VDD, the C-type LCD bias
can only be selected as VA=VOREG.
Bit 2~0 When the charge pump output voltage is equal to 2×VDD, the C-type LCD bias can be selected as
VA=VOREG or VA=VOREG×1.5.
When the C-type LCD voltage is selected to be pumped to VOREGx1.5, the power supply to VDD
should be limited to 2.6V~5.5V.
COM4/SEG27 COM5/SEG26 COM6/SEG25 COM7/SEG24
SEG×COM
(Maximum)
CCS[2:0]
DUTY
000
1/4
SEG27
SEG26
SEG25
SEG24
28×4
001
1/5
COM4
SEG26
SEG25
SEG24
27×5
010
1/6
COM4
COM5
SEG25
SEG24
26×6
011
1/7
COM4
COM5
COM6
SEG24
25×7
1××
1/8
COM4
COM5
COM6
COM7
24×8
The LCDOUT register is used to determine if the output function of LCD pins SEG0~SEG7 are
used a LCD segment drivers or normal I/O operation.
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LCDOUT Register
Bit
7
6
5
4
3
2
1
0
Name
LCDS7
LCDS6
LCDS5
LCDS4
LCDS3
LCDS2
LCDS1
LCDS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7
LCDS7: Select SEG7 or I/O
0: I/O
1: SEG7
Bit 6 LCDS6: Select SEG6 or I/O
0: I/O
1: SEG6
Bit 5 LCDS5: Select SEG5 or I/O
0: I/O
1: SEG5
Bit 4 LCDS4: Select SEG4 or I/O
0: I/O
1: SEG4
Bit 3
LCDS3: Select SEG3 or I/O
0: I/O
1: SEG3
Bit 2 LCDS2: Select SEG2 or I/O
0: I/O
1: SEG2
Bit 1 LCDS1: Select SEG1 or I/O
0: I/O
1: SEG1
Bit 0 LCDS0: Select SEG0 or I/O
0: I/O
1: SEG0
LCD Clock
The LCD clock is driven by the fSUB clock, which then passes through a divider, the division ratio of
which is selected by the LCD clock selection bits, LCDCK1 and LCDCK0, in the CTRL0 register
to provide a LCD clock frequency of fSUB/3, fSUB /4 or fSUB /8. The LCD clock source fSUB can be
derived from the LIRC or LXT oscillator selected by the selection bit, named FSUBS. Note that the
fSUB clock can be enabled or disabled in the power down mode by the fSUB clock control bit FSUBC
in the CTRL0 register.
LCD Driver Output
The output structure of the device LCD driver can be 24×8 to 28×4. The LCD driver bias type has
R and C type. The C/R type and number of COM and SEG is selected by software option. The LCD
driver has a fixed 1/3 bias.
The nature of Liquid Crystal Displays require that only AC voltages can be applied to their pixels
as the application of DC voltages to LCD pixels may cause permanent damage. For this reason
the relative contrast of an LCD display is controlled by the actual RMS voltage applied to each
pixel, which is equal to the RMS value of the voltage on the COM pin minus the voltage applied
to the SEG pin. This differential RMS voltage must be greater than the LCD saturation voltage
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for the pixel to be on and less than the threshold voltage for the pixel to be off. The requirement
to limit the DC voltage to zero and to control as many pixels as possible with a minimum number
of connections, requires that both a time and amplitude signal is generated and applied to the
application LCD. These time and amplitude varying signals are automatically generated by the LCD
driver circuits in the microcontroller. What is known as the duty determines the number of common
lines used, which are also known as backplanes or COMs. The duty, which is chosen by control bits
to have a value of 1/4, 1/5, 1/6 or 1/7, 1/8 and which equates to a COM number of 3, 4, 5, 6 and
7 respectively, therefore defines the number of time divisions within each LCD signal frame. The
accompanying timing diagrams depict the LCD signals generated by the microcontroller for various
values of duty and bias.
LCD Voltage Source and Biasing
The time and amplitude varying signals generated by the LCD Driver function require the generation
of several voltage levels for their operation. The number of voltage levels used by the signal depends
upon the value of the CSSn bits in the LCDC register. The device can have either R type or C type
biasing selected via the RCS bit in the LCDC register. Selecting the C type biasing will enable an
internal charge pump whose multiplying ration can be selected using an additional configuration
option.
For R type biasing an external LCD voltage source is supplied by the internal VLCD biasing
voltage. This could be the microcontroller power supply or some other voltage source. For the
R type 1/3 bias selection, three voltage levels VSS, VA, VB and VC are utilised. The voltage VA
is equal to VLCD. VB is equal to 2/3×VLCD. VC is equal to 1/3×VLCD. Note that no external
capacitors or resistors are required to be connected if R type biasing is used.
For C type biasing an external LCD voltage source also is supplied by the internal VLCD biasing
voltage or VMAX. The C type biasing scheme uses an internal charge pump circuit, which in the
case of the 1/3 bias can generate voltages higher than what is supplied by VLCD. This feature
is useful in applications where the microcontroller supply voltage is less than the supply voltage
required by the LCD.
The bit “VAS” is selected for VA voltage in C type LCD. The relation of LCD voltage is as
following figure.

Note: 1. 1/3bias, VAS= 1, → VAB is VA.
2. 1/3bias, VAS= 0, → VAB is VB.
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Programming Considerations
Certain precautions must be taken when programming the LCD. One of these is to ensure that
the LCD memory is properly initialised after the microcontroller is powered on. Like the General
Purpose Data Memory, the contents of the LCD memory are in an unknown condition after poweron. As the contents of the LCD memory will be mapped into the actual LCD, it is important to
initialise this memory area into a known condition soon after applying power to obtain a proper
display pattern.
Consideration must also be given to the capacitive load of the actual LCD used in the application.
As the load presented to the microcontroller by LCD pixels can be generally modeled as mainly
capacitive in nature, it is important that this is not excessive, a point that is particularly true in the
case of the COM lines which may be connected to many LCD pixels. The accompanying diagram
depicts the equivalent circuit of the LCD.
With such a frequency chosen, the microcontroller internal LCD driver circuits will ensure that the
appropriate LCD driving signals are generated to obtain a suitable LCD frame frequency.
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Configuration Options
Configuration options refer to certain options within the MCU that are programmed into the OTP
Program Memory device during the programming process. During the development process,
these options are selected using the HT-IDE software development tools. As these options are
programmed into the device using the hardware programming tools, once they are selected they
cannot be changed later by the application software. All options must be defined for proper system
function, the details of which are shown in the table.
No.
Options
Oscillator Options
1
System Oscillator Selection - fSYS:
1. HXT
2. ERC
3. HIRC
2
HIRC frequency Selection:
1. 4MHz
2. 8MHz
3. 12MHz
3
External 32kHz Oscillator Selection:
1. I/O
2. 32.768kHz external crystal
4
System Oscillator SST period Selection:
1.1024 clocks
2.2 clocks
Reset Pin Options
5
PA7/RES Pin Options:
1. RES pin
2. I/O pin
LCD Options
6
LCD function in Power down mode:
1. Enable
2. Disable
7
R type drive current selection:
1. 50μA
2. 100μA
Watchdog Options
Rev. 1.20
8
WDT Function
1. Always enable
2. WDT enable/disable by S/W
9
WDT clock Selection - fS:
1. Internal 12kHz RC oscillator - LIRC
2. fSYS/4
3. 32.768kHz oscillator
10
CLRWDT instruction Selection:
1. instruction
2. instruction
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Body Fat Measurement Function
The body fat circuit consists of a sine wave generator, an amplifier and a filter. The circuit has been
designed for maximum flexibility and has a high degree of functional integration to implement a
body fat measurement function.
Sine Wave Generator
The sine wave generator consists of a frequency divider, counter, RAM, 10-bit DAC and OP0.
The circuit can generate a sine wave output with a frequency range of 5kHz~50kHz using a 32×9
bit RAM for the sine wave pattern simulation. The frequency divider will multiply by DN/M to
generate a clock for the counter. The following points must be noted to understand how the sine
wave is generated:
●● System clock/M = sine wave frequency
●● System clock × (DN/M) = the count rate of the counter
●● M must be a multiple of N and 8.
●● M = N×DN
●● DNR = DN/2
●● DN: sine wave cycle data numerical value (DN <= 64)
●● DNR: the data numerical value of the 1/2 sine wave cycle stored in RAM (DNR <= 32)
Refer to the following table and figure for more details.
System Frequency
4MHz
8MHz
12MHz
Sine Wave
Frequency (kHz)
50
5
50
5
50
5
M
80
800
160
1600
240
2400
N
2
16
4
25
4
40
DN
40
50
40
64
60
60
DNR
20
25
20
32
30
30
511
.
0
P0
P2
P1
.
.
PDNR-3 PDNR-1
PDNR-2
- 512
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Only a half sine wave pattern P0~PDNR-1 is generated which is stored in RAM bank 2 with an address
range of 40H~7FH. The sine wave pattern data bits [7:0] are stored with even addresses while the
sine wave pattern data bit [8] is stored with an odd address. Once the sine wave generator is enabled,
the CPU will not be able to write or read data to/from this RAM area. The sine generator will read
the RAM data and transmit it to the 10-bit DAC.
The device will read the half sine wave pattern from the RAM and generate the actual sine
waveform on the SIN pin. Refer to the following diagram:
DN_CNT/2 >= DNR
“0”
“1”
0
D[9]
1
SINE[8:0]
0
2's
Complement
40H
SINE1[7:0]
SINE0[8:0]
SINE1[8:0]
SINE2[8:0]
SINE3[8:0]
.
.
.
.
.
SINE30[8:0]
SINE31[8:0]
SINE32[8:0]
SINE33[8:0]
SINE1[8]
.
.
.
7BH
SINE30[7:0]
SINE30[
8]
7DH
7EH
SINE31[7:0]
SINE31[
8]
7FH
SINE Wave Pattern
RAM(Bank 2)
Rev. 1.20
DAC
D[9:0]
SINE0[8]
43H
7CH
+
1
SINE0[7:0]
41H
42H
D[8:0]
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
SGC Register
Bit
7
6
5
4
3
2
1
0
Name
SGEN
—
—
BREN
—
—
—
—
R/W
R/W
—
—
R/W
—
—
—
—
POR
0
—
—
0
0
0
0
0
Bit 7 SGEN: sine generator enable bit
0: disable
1: enable
When this bit is equal to “0”, the OP0 and 10-bit DAC will be in a power down mode.
Bit 6~5 Unimplemented, read as “0”
Bit 4
BREN: Bias resistor enable
0: disable - power down mode
1: enable - normal mode
When this bit is enabled, it will generate a 0.5×VOREG voltage for the non-inverting
input of OPA1 and OPA2.
Bit 3~0 Unimplemented, read as “0”
SGN Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
D5
D4
D3
D2
D1
D0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
0
0
0
0
0
0
Bit 7~6 Bit 5~0 Unimplemented, read as “0”
D5~D0: system frequency multiplicator - N
Multiplicator (N) equal to D [5:0] + 1
SGDNR Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
D4
D3
D2
D1
D0
R/W
—
—
—
R/W
R/W
R/W
R/W
R/W
POR
—
—
—
0
0
0
0
0
Bit 7~5 Bit 4~0 Unimplemented, read as “0”
D4~D0: 1/2 sine wave cycle numerical value stored in RAM bank 2
DNR is equal to D [4:0] + 1
Amplifier
The amplifier consists of OP1, OP2, a 6-bit DAC and analog switches. OP2 is a differential amplifier
with 1~5 multiple gain. The 6-bit DAC offers a reference voltage to the non-inverting input of OP2.
The user can turn on and off switch 0 to 7 to obtain a reference resistor voltage and a body resistor
voltage.
The body and reference impedance can be obtained by using the SW0 ~ SW7 switches. Refer to
following table for this impedance switching.
Switch
SW0
Foot Impedance
O
SW1
Reference 1KΩ
O
Reference 200Ω
O
SW2
SW3
SW4
O
O
SW5
SW6
SW7
O
O
O
O
O: switch closed.
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
OPAC Register
Bit
7
6
5
4
3
2
1
0
Name
OPAEN
—
—
—
OP2G3
OP2G2
OP2G1
OP2G0
R/W
R/W
—
—
—
R/W
R/W
R/W
R/W
POR
0
—
—
—
0
0
0
0
Bit 7 OPAEN: amplifier enable control
0: enable
1: disable
When this bit is equal to “1”, OP1, OP2 and the 6-bit DAC will be in a power down mode.
Bit 6~4 Unimplemented, read as “0”
Bit 3~0
OP2G3~OP2G0: OP2 gain control
0001: 1.14
0010: 1.31
0011: 1.5
0100: 1.73
0101: 2
0110: 2.33
0111: 2.75
1000: 3.285
1001: 4
1010: 5
Others: 1
SWC Register
Rev. 1.20
Bit
7
6
5
4
3
2
1
0
Name
SW7
SW6
SW5
SW4
SW3
SW2
SW1
SW0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 SW7: switch 7 control bit
0: open
1: short
Bit 6 SW6: switch 6 control bit
0: open
1: short
Bit 5 SW5: switch 5 control bit
0: open
1: short
Bit 4 SW4: switch 4 control bit
0: open
1: short
Bit 3 SW3: switch 3 control bit
0: open
1: short
Bit 2 SW2: switch 2 control bit
0: open
1: short
Bit 1 SW1: switch 1 control bit
0: open
1: short
Bit 0 SW0: switch 0 control bit
0: open
1: short
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May 30, 2013
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
DACO Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
D5
D4
D3
D2
D1
D0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
0
0
0
0
0
0
Bit 7~6 Bit 5~0 Unimplemented, read as “0”
D5~D0: 6-bit DAC output voltage
output voltage = 0.5VOREG * ((D[5:0] + 1)/64)
Filter
The filter consists of CP0, a PMOS transistor and some analog switches. The filter contains a peak
detection function for which an external capacitor will store the peak value for transmission to the
ADC. Switches SW8 and SW9 are for capacitor discharge purposes.
FTRC Register
Bit
7
6
5
4
3
2
1
0
Name
FTREN
—
—
—
—
—
SW9
SW8
R/W
R/W
—
—
—
—
—
R/W
R/W
POR
0
—
—
—
—
—
0
0
Bit 7 FTREN: filter enable
0: disable
1: enable
When this bit is equal to “0”, CP0 and the PMOS transistor will be in a power down mode.
Bit 6~5 Unimplemented, read as “0”
Bit 4
Rev. 1.20
Reserved – must be cleared to “0”
Bit 3~2
Unimplemented, read as “0”
Bit 1 SW9: switch 9 control bit
0: open
1: short
Bit 0 SW8: switch 8 control bit
0: open
1: short
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Application Circuits




































 
 























 


 
 

 















Rev. 1.20
88
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Instruction Set
Introduction
Central to the successful operation of any microcontroller is its instruction set, which is a set of
program instruction codes that directs the microcontroller to perform certain operations. In the case
of Holtek microcontrollers, a comprehensive and flexible set of over 60 instructions is provided to
enable programmers to implement their application with the minimum of programming overheads.
For easier understanding of the various instruction codes, they have been subdivided into several
functional groupings.
Instruction Timing
Most instructions are implemented within one instruction cycle. The exceptions to this are branch,
call, or table read instructions where two instruction cycles are required. One instruction cycle is
equal to 4 system clock cycles, therefore in the case of an 8MHz system oscillator, most instructions
would be implemented within 0.5μs and branch or call instructions would be implemented within
1μs. Although instructions which require one more cycle to implement are generally limited to
the JMP, CALL, RET, RETI and table read instructions, it is important to realize that any other
instructions which involve manipulation of the Program Counter Low register or PCL will also take
one more cycle to implement. As instructions which change the contents of the PCL will imply a
direct jump to that new address, one more cycle will be required. Examples of such instructions
would be "CLR PCL" or "MOV PCL, A". For the case of skip instructions, it must be noted that if
the result of the comparison involves a skip operation then this will also take one more cycle, if no
skip is involved then only one cycle is required.
Moving and Transferring Data
The transfer of data within the microcontroller program is one of the most frequently used
operations. Making use of three kinds of MOV instructions, data can be transferred from registers to
the Accumulator and vice-versa as well as being able to move specific immediate data directly into
the Accumulator. One of the most important data transfer applications is to receive data from the
input ports and transfer data to the output ports.
Arithmetic Operations
The ability to perform certain arithmetic operations and data manipulation is a necessary feature of
most microcontroller applications. Within the Holtek microcontroller instruction set are a range of
add and subtract instruction mnemonics to enable the necessary arithmetic to be carried out. Care
must be taken to ensure correct handling of carry and borrow data when results exceed 255 for
addition and less than 0 for subtraction. The increment and decrement instructions INC, INCA, DEC
and DECA provide a simple means of increasing or decreasing by a value of one of the values in the
destination specified.
Logical and Rotate Operations
The standard logical operations such as AND, OR, XOR and CPL all have their own instruction
within the Holtek microcontroller instruction set. As with the case of most instructions involving
data manipulation, data must pass through the Accumulator which may involve additional
programming steps. In all logical data operations, the zero flag may be set if the result of the
operation is zero. Another form of logical data manipulation comes from the rotate instructions such
as RR, RL, RRC and RLC which provide a simple means of rotating one bit right or left. Different
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
rotate instructions exist depending on program requirements. Rotate instructions are useful for serial
port programming applications where data can be rotated from an internal register into the Carry
bit from where it can be examined and the necessary serial bit set high or low. Another application
where rotate data operations are used is to implement multiplication and division calculations.
Branches and Control Transfer
Program branching takes the form of either jumps to specified locations using the JMP instruction or
to a subroutine using the CALL instruction. They differ in the sense that in the case of a subroutine
call, the program must return to the instruction immediately when the subroutine has been carried
out. This is done by placing a return instruction RET in the subroutine which will cause the program
to jump back to the address right after the CALL instruction. In the case of a JMP instruction, the
program simply jumps to the desired location. There is no requirement to jump back to the original
jumping off point as in the case of the CALL instruction. One special and extremely useful set
of branch instructions are the conditional branches. Here a decision is first made regarding the
condition of a certain data memory or individual bits. Depending upon the conditions, the program
will continue with the next instruction or skip over it and jump to the following instruction. These
instructions are the key to decision making and branching within the program perhaps determined
by the condition of certain input switches or by the condition of internal data bits.
Bit Operations
The ability to provide single bit operations on Data Memory is an extremely flexible feature of all
Holtek microcontrollers. This feature is especially useful for output port bit programming where
individual bits or port pins can be directly set high or low using either the "SET [m].i" or "CLR [m].
i" instructions respectively. The feature removes the need for programmers to first read the 8-bit
output port, manipulate the input data to ensure that other bits are not changed and then output the
port with the correct new data. This read-modify-write process is taken care of automatically when
these bit operation instructions are used.
Table Read Operations
Data storage is normally implemented by using registers. However, when working with large
amounts of fixed data, the volume involved often makes it inconvenient to store the fixed data in
the Data Memory. To overcome this problem, Holtek microcontrollers allow an area of Program
Memory to be setup as a table where data can be directly stored. A set of easy to use instructions
provides the means by which this fixed data can be referenced and retrieved from the Program
Memory.
Other Operations
In addition to the above functional instructions, a range of other instructions also exist such as
the "HALT" instruction for Power-down operations and instructions to control the operation of
the Watchdog Timer for reliable program operations under extreme electric or electromagnetic
environments. For their relevant operations, refer to the functional related sections.
Rev. 1.20
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HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Instruction Set Summary
The following table depicts a summary of the instruction set categorised according to function and
can be consulted as a basic instruction reference using the following listed conventions.
Table conventions
x: Bits immediate data
m: Data Memory address
A: Accumulator
i: 0~7 number of bits
addr: Program memory address
Mnemonic
Description
Cycles
Flag Affected
ADD A,[m]
ADDM A,[m]
ADD A,x
ADC A,[m]
ADCM A,[m]
SUB A,x
SUB A,[m]
SUBM A,[m]
SBC A,[m]
SBCM A,[m]
DAA [m]
Logic Operation
Add Data Memory to ACC
Add ACC to Data Memory
Add immediate data to ACC
Add Data Memory to ACC with Carry
Add ACC to Data memory with Carry
Subtract immediate data from the ACC
Subtract Data Memory from ACC
Subtract Data Memory from ACC with result in Data Memory
Subtract Data Memory from ACC with Carry
Subtract Data Memory from ACC with Carry, result in Data Memory
Decimal adjust ACC for Addition with result in Data Memory
1
1Note
1
1
1Note
1
1
1Note
1
1Note
1Note
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
C
AND A,[m]
OR A,[m]
XOR A,[m]
ANDM A,[m]
ORM A,[m]
XORM A,[m]
AND A,x
OR A,x
XOR A,x
CPL [m]
CPLA [m]
Logical AND Data Memory to ACC
Logical OR Data Memory to ACC
Logical XOR Data Memory to ACC
Logical AND ACC to Data Memory
Logical OR ACC to Data Memory
Logical XOR ACC to Data Memory
Logical AND immediate Data to ACC
Logical OR immediate Data to ACC
Logical XOR immediate Data to ACC
Complement Data Memory
Complement Data Memory with result in ACC
1
1
1
1Note
1Note
1Note
1
1
1
1Note
1
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Arithmetic
Increment & Decrement
INCA [m]
INC [m]
DECA [m]
DEC [m]
Increment Data Memory with result in ACC
Increment Data Memory
Decrement Data Memory with result in ACC
Decrement Data Memory
1
1Note
1
1Note
Z
Z
Z
Z
Rotate
RRA [m]
RR [m]
RRCA [m]
RRC [m]
RLA [m]
RL [m]
RLCA [m]
RLC [m]
Rotate Data Memory right with result in ACC
Rotate Data Memory right
Rotate Data Memory right through Carry with result in ACC
Rotate Data Memory right through Carry
Rotate Data Memory left with result in ACC
Rotate Data Memory left
Rotate Data Memory left through Carry with result in ACC
Rotate Data Memory left through Carry
1
1Note
1
1Note
1
1Note
1
1Note
None
None
C
C
None
None
C
C
Rev. 1.20
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Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Mnemonic
Description
Cycles
Flag Affected
Move Data Memory to ACC
Move ACC to Data Memory
Move immediate data to ACC
1
1Note
1
None
None
None
Clear bit of Data Memory
Set bit of Data Memory
1Note
1Note
None
None
Jump unconditionally
Skip if Data Memory is zero
Skip if Data Memory is zero with data movement to ACC
Skip if bit i of Data Memory is zero
Skip if bit i of Data Memory is not zero
Skip if increment Data Memory is zero
Skip if decrement Data Memory is zero
Skip if increment Data Memory is zero with result in ACC
Skip if decrement Data Memory is zero with result in ACC
Subroutine call
Return from subroutine
Return from subroutine and load immediate data to ACC
Return from interrupt
2
1Note
1Note
1Note
1Note
1Note
1Note
1Note
1Note
2
2
2
2
None
None
None
None
None
None
None
None
None
None
None
None
None
Read table (current page) to TBLH and Data Memory
Read table (last page) to TBLH and Data Memory
2Note
2Note
None
None
No operation
Clear Data Memory
Set Data Memory
Clear Watchdog Timer
Pre-clear Watchdog Timer
Pre-clear Watchdog Timer
Swap nibbles of Data Memory
Swap nibbles of Data Memory with result in ACC
Enter power down mode
1
1Note
1Note
1
1
1
1Note
1
1
None
None
None
TO, PDF
TO, PDF
TO, PDF
None
None
TO, PDF
Data Move
MOV A,[m]
MOV [m],A
MOV A,x
Bit Operation
CLR [m].i
SET [m].i
Branch
JMP addr
SZ [m]
SZA [m]
SZ [m].i
SNZ [m].i
SIZ [m]
SDZ [m]
SIZA [m]
SDZA [m]
CALL addr
RET
RET A,x
RETI
Table Read
TABRDC [m]
TABRDL [m]
Miscellaneous
NOP
CLR [m]
SET [m]
CLR WDT
CLR WDT1
CLR WDT2
SWAP [m]
SWAPA [m]
HALT
Note: 1. For skip instructions, if the result of the comparison involves a skip then two cycles are required,
if no skip takes place only one cycle is required.
2. Any instruction which changes the contents of the PCL will also require 2 cycles for execution.
3. For the "CLR WDT1" and "CLR WDT2" instructions the TO and PDF flags may be affected
by the execution status. The TO and PDF flags are cleared after both "CLR WDT1" and "CLR
WDT2" instructions are consecutively executed. Otherwise the TO and PDF flags remain
unchanged.
Rev. 1.20
92
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Instruction Definition
ADC A,[m]
Add Data Memory to ACC with Carry
Description
The contents of the specified Data Memory, Accumulator and the carry flag are
added. The result is stored in the Accumulator.
Operation
ACC ← ACC + [m] + C
Affected flag(s)
OV, Z, AC, C
ADCM A,[m]
Add ACC to Data Memory with Carry
Description
The contents of the specified Data Memory, Accumulator and the carry flag are
added. The result is stored in the specified Data Memory.
Operation
[m] ← ACC + [m] + C
Affected flag(s)
OV, Z, AC, C
ADD A,[m]
Add Data Memory to ACC
Description
The contents of the specified Data Memory and the Accumulator are added. The
result is stored in the Accumulator.
Operation
ACC ← ACC + [m]
Affected flag(s)
OV, Z, AC, C
ADD A,x
Add immediate data to ACC
Description
The contents of the Accumulator and the specified immediate data are added. The
result is stored in the Accumulator.
Operation
AC ← ACC + x
Affected flag(s)
OV, Z, AC, C
ADDM A,[m]
Add ACC to Data Memory
Description
The contents of the specified Data Memory and the Accumulator are added. The
result is stored in the specified Data Memory.
Operation
[m] ← ACC + [m]
Affected flag(s)
OV, Z, AC, C
AND A,[m]
Logical AND Data Memory to ACC
Description
Data in the Accumulator and the specified Data Memory perform a bitwise logical
AND operation. The result is stored in the Accumulator.
Operation
ACC ← ACC "AND" [m]
Affected flag(s)
Z
AND A,x
Logical AND immediate data to ACC
Description
Data in the Accumulator and the specified immediate data perform a bitwise logical
AND operation. The result is stored in the Accumulator.
Operation
ACC ← ACC "AND"x
Affected flag(s)
Z
ANDM A,[m]
Logical AND ACC to Data Memory
Description
Data in the specified Data Memory and the Accumulator perform a bitwise logical
AND operation. The result is stored in the Data Memory.
Operation
[m] ← ACC "AND" [m]
Affected flag(s)
Z
Rev. 1.20
93
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
CALL addr
Subroutine call
Description
Unconditionally calls a subroutine at the specified address. The Program Counter
then increments by 1 to obtain the address of the next instruction which is then
pushed onto the stack. The specified address is then loaded and the program
continues execution from this new address. As this instruction requires an
additional operation, it is a two cycle instruction.
Operation
Stack ← Program Counter + 1
Program Counter ← addr
Affected flag(s)
None
CLR [m]
Clear Data Memory
Description
Each bit of the specified Data Memory is cleared to 0.
Operation
[m] ← 00H
Affected flag(s)
None
CLR [m].i
Clear bit of Data Memory
Description
Bit i of the specified Data Memory is cleared to 0.
Operation
[m].i ← 0
Affected flag(s)
None
CLR WDT
Clear Watchdog Timer
Description
The TO, PDF flags and the WDT are all cleared.
Operation
WDT cleared
TO ← 0
PDF ← 0
Affected flag(s)
TO, PDF
CLR WDT1
Pre-clear Watchdog Timer
Description
The TO, PDF flags and the WDTare all cleared. Note that this instruction works in
conjunction with CLR WDT2 and must be executed alternately with CLR WDT2
to have effect. Repetitively executing this instruction without alternately executing
CLR WDT2 will have no effect.
Operation
WDT cleared
TO ← 0
PDF ← 0
Affected flag(s)
TO, PDF
CLR WDT2
Pre-clear Watchdog Timer
Description
The TO, PDF flags and the WDTare all cleared. Note that this instruction works in
conjunction with CLR WDT1 and must be executed alternately with CLR WDT1
to have effect. Repetitively executing this instruction without alternately executing
Operation
WDT cleared
TO ← 0
PDF ← 0
Affected flag(s)
Rev. 1.20
TO, PDF
94
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
CPL [m]
Complement Data Memory
Description
Each bit of the specified Data Memory is logically complemented (1's complement).
Bits which previously contained a 1 are changed to 0 and vice versa.
[m] ← [m]
Operation
Z
Affected flag(s)
Complement Data Memory with result in ACC
CPLA [m]
Each bit of the specified Data Memory is logically complemented (1's
Description
complement). Bits which previously contained a 1 are changed to 0 and vice versa.
The complemented result is stored in the Accumulator and the contents of the Data
Memory remain unchanged.
ACC ← [m]
Operation
Z
Affected flag(s)
Decimal-Adjust ACC for addition with result in Data Memory
DAA [m]
Convert the contents of the Accumulator value to a BCD ( Binary Coded Decimal)
Description
value resulting from the previous addition of two BCD variables. If the low nibble is
greater than 9 or if AC flag is set, then a value of 6 will be added to the low nibble.
Otherwise the low nibble remains unchanged. If the high nibble is greater than 9
or if the C flag is set, then a value of 6 will be added to the high nibble. Essentially,
the decimal conversion is performed by adding 00H, 06H, 60H or 66H depending
on the Accumulator and flag conditions. Only the C flag may be affected by this
instruction which indicates that if the original BCD sum is greater than 100, it allows
multiple precision decimal addition.
[m] ← ACC + 00H or
Operation
[m] ← ACC + 06H or
[m] ← ACC + 60H or
[m] ← ACC + 66H
C
Affected flag(s)
Decrement Data Memory
DEC [m]
Data in the specified Data Memory is decremented by 1.
Description
[m] ← [m] – 1
Operation
Z
Affected flag(s)
Decrement Data Memory with result in ACC
DECA [m]
Data in the specified Data Memory is decremented by 1. The result is stored in the
Description
Accumulator. The contents of the Data Memory remain unchanged.
ACC ← [m] – 1
Operation
Z
Affected flag(s)
Rev. 1.20
95
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
HALT
Enter power down mode
Description
This instruction stops the program execution and turns off the system clock. The
contents of the Data Memory and registers are retained. The WDT and prescaler
are cleared. The power down flag PDF is set and the WDT time-out flag TO is
cleared.
Operation
TO ← 0
PDF ← 0
Affected flag(s)
TO, PDF
INC [m]
Increment Data Memory
Description
Data in the specified Data Memory is incremented by 1.
Operation
[m] ← [m]+1
Affected flag(s)
Z
INCA [m]
Increment Data Memory with result in ACC
Description
Data in the specified Data Memory is incremented by 1. The result is stored in the
Accumulator. The contents of the Data Memory remain unchanged.
Operation
ACC ← [m]+1
Affected flag(s)
Z
JMP addr
Jump unconditionally
Description
The contents of the Program Counter are replaced with the specified address.
Program execution then continues from this new address. As this requires the
insertion of a dummy instruction while the new address is loaded, it is a two cycle
instruction.
Operation
Program Counter ← addr
Affected flag(s)
None
MOV A,[m]
Move Data Memory to ACC
Description
The contents of the specified Data Memory are copied to the Accumulator.
Operation
ACC ← [m]
Affected flag(s)
None
MOV A,x
Move immediate data to ACC
Description
The immediate data specified is loaded into the Accumulator.
Operation
ACC ← x
Affected flag(s)
None
MOV [m],A
Move ACC to Data Memory
Description
The contents of the Accumulator are copied to the specified Data Memory.
Operation
[m] ← ACC
Affected flag(s)
None
NOP
No operation
Description
No operation is performed. Execution continues with the next instruction.
Operation
No operation
Affected flag(s)
None
Rev. 1.20
96
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
OR A,[m]
Logical OR Data Memory to ACC
Description
Data in the Accumulator and the specified Data Memory perform a bitwise logical
OR operation. The result is stored in the Accumulator.
Operation
ACC ← ACC "OR" [m]
Affected flag(s)
Z
OR A,x
Logical OR immediate data to ACC
Description
Data in the Accumulator and the specified immediate data perform a bitwise logical
OR operation. The result is stored in the Accumulator.
Operation
ACC ← ACC "OR" x
Affected flag(s)
Z
ORM A,[m]
Logical OR ACC to Data Memory
Description
Data in the specified Data Memory and the Accumulator perform a bitwise logical
OR operation. The result is stored in the Data Memory.
Operation
[m] ← ACC "OR" [m]
Affected flag(s)
Z
RET
Return from subroutine
Description
The Program Counter is restored from the stack. Program execution continues at
the restored address.
Operation
Program Counter ← Stack
Affected flag(s)
None
RET A,x
Return from subroutine and load immediate data to ACC
Description
The Program Counter is restored from the stack and the Accumulator loaded
with the specified immediate data. Program execution continues at the restored
address.
Operation
Program Counter ← Stack
ACC ← x
Affected flag(s)
None
RETI
Return from interrupt
Description
The Program Counter is restored from the stack and the interrupts are re-enabled
by setting the EMI bit. EMI is the master interrupt global enable bit. If an interrupt
was pending when the RETI instruction is executed, the pending Interrupt routine
will be processed before returning to the main program.
Operation
Program Counter ← Stack
EMI ← 1
Affected flag(s)
None
RL [m]
Rotate Data Memory left
Description
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated
into bit 0.
Operation
[m].(i+1) ← [m].i; (i = 0~6)
[m].0 ← [m].7
Affected flag(s)
Rev. 1.20
None
97
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
RLA [m]
Rotate Data Memory left with result in ACC
Description
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated
into bit 0. The rotated result is stored in the Accumulator and the contents of the
Data Memory remain unchanged.
Operation
ACC.(i+1) ← [m].i; (i = 0~6)
ACC.0 ← [m].7
Affected flag(s)
None
RLC [m]
Rotate Data Memory left through Carry
Description
The contents of the specified Data Memory and the carry flag are rotated left by 1
bit. Bit 7 replaces the Carry bit and the original carry flag is rotated into bit 0.
Operation
[m].(i+1) ← [m].i; (i = 0~6)
[m].0 ← C
C ← [m].7
Affected flag(s)
C
RLCA [m]
Rotate Data Memory left through Carry with result in ACC
Description
Data in the specified Data Memory and the carry flag are rotated left by 1 bit. Bit 7
replaces the Carry bit and the original carry flag is rotated into the bit 0. The rotated
result is stored in the Accumulator and the contents of the Data Memory remain
unchanged.
Operation
ACC.(i+1) ← [m].i; (i = 0~6)
ACC.0 ← C
C ← [m].7
Affected flag(s)
C
RR [m]
Rotate Data Memory right
Description
The contents of the specified Data Memory are rotated right by 1 bit with bit 0
rotated into bit 7.
Operation
[m].i ← [m].(i+1); (i = 0~6)
[m].7 ← [m].0
Affected flag(s)
None
RRA [m]
Rotate Data Memory right with result in ACC
Description
Data in the specified Data Memory and the carry flag are rotated right by 1 bit
with bit 0 rotated into bit 7. The rotated result is stored in the Accumulator and the
contents of the Data Memory remain unchanged.
Operation
ACC.i ← [m].(i+1); (i = 0~6)
ACC.7 ← [m].0
Affected flag(s)
None
RRC [m]
Rotate Data Memory right through Carry
Description
The contents of the specified Data Memory and the carry flag are rotated right by 1
bit. Bit 0 replaces the Carry bit and the original carry flag is rotated into bit 7.
Operation
[m].i ← [m].(i+1); (i = 0~6)
[m].7 ← C
C ← [m].0
Affected flag(s)
Rev. 1.20
C
98
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
RRCA [m]
Rotate Data Memory right through Carry with result in ACC
Description
Data in the specified Data Memory and the carry flag are rotated right by 1 bit. Bit
0 replaces the Carry bit and the original carry flag is rotated into bit 7. The rotated
result is stored in the Accumulator and the contents of the Data Memory remain
unchanged.
Operation
ACC.i ← [m].(i+1); (i = 0~6)
ACC.7 ← C
C ← [m].0
Affected flag(s)
C
SBC A,[m]
Subtract Data Memory from ACC with Carry
Description
The contents of the specified Data Memory and the complement of the carry flag
are subtracted from the Accumulator. The result is stored in the Accumulator. Note
that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise
if the result is positive or zero, the C flag will be set to 1.
Operation
ACC ← ACC – [m] – C
Affected flag(s)
OV, Z, AC, C
SBCM A,[m]
Subtract Data Memory from ACC with Carry and result in Data Memory
Description
The contents of the specified Data Memory and the complement of the carry flag
are subtracted from the Accumulator. The result is stored in the Data Memory. Note
that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise
if the result is positive or zero, the C flag will be set to 1.
Operation
ACC ← ACC – [m] – C
Affected flag(s)
OV, Z, AC, C
SDZ [m]
Skip if decrement Data Memory is 0
Description
The contents of the specified Data Memory are first decremented by 1. If the result
is 0 the following instruction is skipped. As this requires the insertion of a dummy
instruction while the next instruction is fetched, it is a two cycle instruction. If the
result is not 0 the program proceeds with the following instruction.
Operation
[m] ← [m] – 1
Skip if [m] = 0
Affected flag(s)
None
SDZA [m]
Skip if decrement Data Memory is zero with result in ACC
Description
The contents of the specified Data Memory are first decremented by 1. If the result
is 0, the following instruction is skipped. The result is stored in the Accumulator
but the specified Data Memory contents remain unchanged. As this requires the
insertion of a dummy instruction while the next instruction is fetched, it is a two
cycle instruction. If the result is not 0, the program proceeds with the following
Operation
instruction.
ACC ← [m] – 1
Affected flag(s)
Skip if ACC = 0
None
Rev. 1.20
99
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
SET [m]
Set Data Memory
Description
Each bit of the specified Data Memory is set to 1.
Operation
[m] ← FFH
Affected flag(s)
None
SET [m].i
Set bit of Data Memory
Description
Bit i of the specified Data Memory is set to 1.
Operation
[m].1 ← 1
Affected flag(s)
None
SIZ [m]
Skip if increment Data Memory is 0
Description
The contents of the specified Data Memory are first incremented by 1. If the result
is 0, the following instruction is skipped. As this requires the insertion of a dummy
instruction while the next instruction is fetched, it is a two cycle instruction. If the
result is not 0 the program proceeds with the following instruction.
Operation
[m] ← [m] + 1
Skip if [m] = 0
Affected flag(s)
None
SIZA [m]
Skip if increment Data Memory is zero with result in ACC
Description
The contents of the specified Data Memory are first incremented by 1. If the result
is 0, the following instruction is skipped. The result is stored in the Accumulator
but the specified Data Memory contents remain unchanged. As this requires the
insertion of a dummy instruction while the next instruction is fetched, it is a two
cycle instruction. If the result is not 0 the program proceeds with the following
instruction.
Operation
ACC ← [m] + 1
Skip if ACC = 0
Affected flag(s)
None
SNZ [m].i
Skip if bit i of Data Memory is not 0
Description
If bit i of the specified Data Memory is not 0, the following instruction is skipped.
As this requires the insertion of a dummy instruction while the next instruction is
fetched, it is a two cycle instruction. If the result is 0 the program proceeds with the
following instruction.
Operation
Skip if [m].i ≠ 0
Affected flag(s)
None
SUB A,[m]
Subtract Data Memory from ACC
Description
The specified Data Memory is subtracted from the contents of the Accumulator. The
result is stored in the Accumulator. Note that if the result of subtraction is negative,
the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag
will be set to 1.
Operation
ACC ← ACC – [m]
Affected flag(s)
OV, Z, AC, C
Rev. 1.20
100
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
SUBM A,[m]
Subtract Data Memory from ACC with result in Data Memory
Description
The specified Data Memory is subtracted from the contents of the Accumulator. The
result is stored in the Data Memory. Note that if the result of subtraction is negative,
the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag
will be set to 1.
Operation
[m] ← ACC – [m]
Affected flag(s)
OV, Z, AC, C
SUB A,x
Subtract immediate data from ACC
Description
The immediate data specified by the code is subtracted from the contents of the
Accumulator. The result is stored in the Accumulator. Note that if the result of
subtraction is negative, the C flag will be cleared to 0, otherwise if the result is
positive or zero, the C flag will be set to 1.
Operation
ACC ← ACC – x
Affected flag(s)
OV, Z, AC, C
SWAP [m]
Swap nibbles of Data Memory
Description
The low-order and high-order nibbles of the specified Data Memory are
interchanged.
Operation
[m].3~[m].0↔[m].7 ~ [m].4
Affected flag(s)
None
SWAPA [m]
Swap nibbles of Data Memory with result in ACC
Description
The low-order and high-order nibbles of the specified Data Memory are
interchanged. The result is stored in the Accumulator. The contents of the Data
Memory remain unchanged.
ACC.3 ~ ACC.0 ← [m].7 ~ [m].4
Operation
ACC.7 ~ ACC.4 ← [m].3 ~ [m].0
Affected flag(s)
None
SZ [m]
Skip if Data Memory is 0
Description
If the contents of the specified Data Memory is 0, the following instruction is
skipped. As this requires the insertion of a dummy instruction while the next
instruction is fetched, it is a two cycle instruction. If the result is not 0 the program
proceeds with the following instruction.
Operation
Skip if [m] = 0
Affected flag(s)
None
SZA [m]
Skip if Data Memory is 0 with data movement to ACC
Description
The contents of the specified Data Memory are copied to the Accumulator. If the
value is zero, the following instruction is skipped. As this requires the insertion of a
dummy instruction while the next instruction is fetched, it is a two cycle instruction.
If the result is not 0 the program proceeds with the following instruction.
Operation
ACC ← [m]
Skip if [m] = 0
Affected flag(s)
Rev. 1.20
None
101
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
SZ [m].i
Skip if bit i of Data Memory is 0
Description
If bit i of the specified Data Memory is 0, the following instruction is skipped. As this
requires the insertion of a dummy instruction while the next instruction is fetched,
it is a two cycle instruction. If the result is not 0, the program proceeds with the
following instruction.
Operation
Skip if [m].i = 0
Affected flag(s)
None
TABRDC [m]
Read table (current page) to TBLH and Data Memory
Description
The low byte of the program code (current page) addressed by the table pointer
(TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
Operation
[m] ← program code (low byte)
TBLH ← program code (high byte)
Affected flag(s)
None
TABRDL [m]
Read table (last page) to TBLH and Data Memory
Description
The low byte of the program code (last page) addressed by the table pointer (TBLP)
is moved to the specified Data Memory and the high byte moved to TBLH.
Operation
[m] ← program code (low byte)
TBLH ← program code (high byte)
Affected flag(s)
None
XOR A,[m]
Logical XOR Data Memory to ACC
Description
Data in the Accumulator and the specified Data Memory perform a bitwise logical
XOR operation. The result is stored in the Accumulator.
Operation
ACC ← ACC "XOR" [m]
Affected flag(s)
Z
XORM A,[m]
Logical XOR ACC to Data Memory
Description
Data in the specified Data Memory and the Accumulator perform a bitwise logical
XOR operation. The result is stored in the Data Memory.
Operation
[m] ← ACC "XOR" [m]
Affected flag(s)
Z
XOR A,x
Logical XOR immediate data to ACC
Description
Data in the Accumulator and the specified immediate data perform a bitwise logical
XOR operation. The result is stored in the Accumulator.
Operation
ACC ← ACC "XOR" x
Affected flag(s)
Z
Rev. 1.20
102
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Package Information
Note that the package information provided here is for consultation purposes only. As this
information may be updated at regular intervals users are reminded to consult the Holtek website for
the latest version of the package information.
Additional supplementary information with regard to packaging is listed below. Click on the relevant
section to be transferred to the relevant website page.
●● Further Package Information (include Outline Dimensions, Product Tape and Reel Specifications)
●● Packing Meterials Information
●● Carton information
●● PB FREE Products
●● Green Packages Products
Rev. 1.20
103
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
80-pin LQFP (10mm × 10mm) Outline Dimensions
Symbol
Nom.
Max.
A
0.469
―
0.476
B
0.390
―
0.398
C
0.469
―
0.476
D
0.390
―
0.398
E
―
0.016
―
F
―
0.006
―
G
0.053
―
0.057
H
―
―
0.063
I
―
0.004
―
J
0.018
―
0.030
K
0.004
―
0.008
α
0°
―
7°
Symbol
Rev. 1.20
Dimensions in inch
Min.
Dimensions in mm
Min.
Nom.
Max.
12.10
A
11.90
―
B
9.90
―
10.10
C
11.90
―
12.10
D
9.90
―
10.10
―
E
―
0.40
F
―
0.16
―
G
1.35
―
1.45
1.60
H
―
―
I
―
0.10
―
J
0.45
―
0.75
K
0.10
―
0.20
α
0°
―
7°
104
May 30, 2013
HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
Copyright© 2013 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time
of publication. However, Holtek assumes no responsibility arising from the use of
the specifications described. The applications mentioned herein are used solely
for the purpose of illustration and Holtek makes no warranty or representation that
such applications will be suitable without further modification, nor recommends
the use of its products for application that may present a risk to human life due to
malfunction or otherwise. Holtek's products are not authorized for use as critical
components in life support devices or systems. Holtek reserves the right to alter
its products without prior notification. For the most up-to-date information, please
visit our web site at http://www.holtek.com.tw.
Rev. 1.20
105
May 30, 2013

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