Renesas RL78G14 Installation and operating instructions

APPLICATION NOTE
RESH-OS-MC-20001 Rev.1.00 Page 1 of 26
Nov 03,2011
RL78/G14
Power Tool 120 deg. Reference Development
Introduction
This document will provide an overview of power tool 120 degree reference development. This solution is based on
Renesas Electronics' next-generation MCU (RL78 family), which combines advanced features from both the 78K and
R8C families. Same as mainstream power tool products in market, BLDC control is used in this solution.
Target Device
RL78/G14 Group
Contents
1. Overview ........................................................................................................................................... 2
2. System Diagram................................................................................................................................ 3
3. Configuration of R5F104BE .............................................................................................................. 4
4. Control theory.................................................................................................................................... 9
5. Hardware structure.......................................................................................................................... 13
6. Hardware and test data................................................................................................................... 19
7. Software flowchart........................................................................................................................... 22
APPENDIX .............................................................................................................................................. 25
RESH-OS-MC-20001
Rev.1.00
Nov 03, 2011

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 2 of 26
Nov 03,2011
1. Overview
1.1 Overview
120 degree control method are widely used in power tool controller, this kind of control mode not only include the
torque variation caused by phase change, but also include the torque variation caused by the step performance caused by
the control theory itself. This project adopts new method to overcome the torque variation on the basis of 120 control
mode.
The RL78 Family is Renesas Electronics' next-generation microcontroller family combining advanced features from
both the 78K and R8C families to deliver low power consumption and high performance. As one member of RL78
family, RL78/G14 achieves reduced system power consumption overall, and supports multifunctional consumer and
industrial applications without requiring additional external components. Since there is built-in three-phase PWM
output timer and two-phase encoder timer: Motor control, it is suitable to be used for Brushless DC motor control.
RL78/G14 is used to develop the 120 degree control method for the power tool controller. The main functions are list
below:
●120 degree sinusoidal wave control;
●Close-loop control of current;
●Three-step speed control;
●Over current protection;
●Thermal protection;
1.2 Electrical Specifications
Size: 50mm(L)*46.8mm(W)
Storage Environment: -20 ~ 85 ℃，40% ~ 95% RH
Operation Environment: 0 ~ 70 ℃，40% ~ 95% RH
Rated Voltage: DC 14V
Rated Current: 3.5A
Rated Power: 50W
Speed: High level: 0～2400 RPM
Middle level: 0～1800 RPM
Low level: 0～1100 RPM

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 3 of 26
Nov 03,2011
2. System Diagram
Figure 2-1 120 degree control system diagram
VDD=14.4V
BLDC
LM317
+
5V
RL78/G14
R5F104BE
Driver IC
L6387
Speed set
Direction set
LED lighting
…………
Strength set
LED Indication

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 4 of 26
Nov 03,2011
3. Configuration of R5F104BE
3.1 Pin of R5F104BE
Figure 3-1 Pin of R5F104BE

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 5 of 26
Nov 03,2011
3.2 Structure of R5F104BE
Figure 3-2 Structure of R5F104BE

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 6 of 26
Nov 03,2011
3.3 Function list of R5F104xx
Table 3-1 Function List
Item R5F104Ax R5F104Bx R5F104Cx R5F104Ex
Pin Count 30 32 36 40
Flash memory
(KB)
16 to 64 16 to 64 16 to 64 16 to 64
RAM (KB) 2.5 to 5.5 2.5 to 5.5 2.5 to 5.5 2.5 to 5.5
Internal
memory
Data Flash (KB) 4 4 4 4
Memory Space 1MB
High-speed
system clock
X1 (crystal/ceramic) oscillation, external main system clock
input (EXCLK)
1 to 20 MHz: VDD = 2.7 to 5.5 V, 1 to 8 MHz: VDD = 1.8 to
2.7 V, 1 to 4 MHz: VDD = 1.6 to 1.8 V
Main
system
Clock
（Oscillation
frequency
）
Internal high-
speed
oscillation
clock
Internal oscillation
64 MHz/48 MHz/32 MHz/24 MHz/16 MHz/12 MHz/8 MHz/4
MHz/1 MHz (TYP.)
Internal low-speed oscillation
clock
(For WDT)
Internal oscillation (Watchdog timer, Real-time clock,
Interval timer clock)
15 kHz (TYP.): VDD = 1.6 to 5.5 V
General-purpose register 8 bits 32 registers (8 bits 8 registers 4 banks)
0.03125 μs (Internal high-speed oscillation clock: fIH = 32
MHz operation)
0.05 μs (High-speed system clock: fMX = 20 MHz
operation)
Minimum instruction
execution time
30.5 μs (Subsystem clock: fSUB = 32.768 kHz operation)
Instruction set • 8-bit operation, 16-bit operation
• Multiplication (8 bits × 8 bits, 16 bits × 16 bits), Division (16
bits ÷ 16 bits, 32 bits ÷ 32 bits)
• Product-sum operation (16 bits × 16 bits + 32 bits)
• Bit manipulation (Set, reset, test, and Boolean operation),
etc.
I/O port
30-pin
produc
ts
32-pin
produc
ts
36-pin
produc
ts
40-pin
product
s
Total 26 28 32 36
CMOS I/O 21 22 26 28
CMOS input 3 3 3 5
CMOS output - - - -
N-ch open-drain
I/O
(6 V tolerance
2 3 3 3

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 7 of 26
Nov 03,2011
Timer
Timer
outputs
• 16-bit timer: 8 channels
• Watchdog timer: 1 channe
• Real-time counter: 1 channel
• Interval timer: 1 channel
A/D converter 8/10-bit resolution 8 channels
Serial interface [30-pin, 32-pin products]
• CSI: 1 channel/UART: 1 channel/simplified I2C: 1 channel
• CSI: 1 channel/UART: 1 channel/simplified I2C: 1 channel
• CSI: 1 channel/UART (UART supporting LIN-bus): 1
channel/simplified I2C: 1 channel
[36-pin, 40-pin products]
• CSI: 1 channel/UART: 1 channel/simplified I2C: 1 channel
• CSI: 1 channel/UART: 1 channel/simplified I2C: 1 channel
• CSI: 2 channels/UART (UART supporting LIN-bus): 1
channel/simplified I2C: 2 channels
Multiplier/divider • 16 bits × 16 bits = 32 bits (Unsigned or signed)
• 16 bits ÷ 16 bits = 16 bits, 32 bits ÷ 32 bits = 32 bits
(Unsigned)
• 16 bits × 16 bits + 32 bits = 32 bits (Unsigned or signed)
Data transfer controller
(DTC)
29 sources
Internal 24Vector
interrupt
source External 7
Reset • Reset by RESET pin
• Internal reset by watchdog timer
• Internal reset by power-on-reset
• Internal reset by voltage detector
• Internal reset by illegal instruction execution Note
• Internal reset by RAM parity error
• Internal reset by illegal-memory access
Voltage detector When voltage rises: between 1.63 V and 3.98 V (14 stages)
When voltage drops: between 1.67 V and 4.06 V (14 stages)
Power supply voltage VDD = 1.6 to 5.5 V
Operating ambient
temperature
TA = -40 to +85 C

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 8 of 26
Nov 03,2011
3.4 Pin function of R5F104BE
Table 3-2 Pin Function Configuration
Pin NO. Pin name Pin Function Note
1 P40/TOOL0 Program interface Input/Ouput
2 RESET Reset Input
3 P137/INTP0 AD analog input over-current
protection
4 P122/X2/EXCLK Not used
5 P121/X1 Not used
6 REGC Group via cap
7 VSS Group
8 VDD Power
9 P60/SCLA0 Direction control Input
10 P61/SDAA0 Strength indication 3 output
11 P62/SSI00 Strength indication 2 output
12 P31/TI03/TO03/INTP4/PCLBUZ0 Strength indication 1 output
13 P70 unused
14 P30/INTP3/SCK00/SCL00/TRJO0 HALL W Input
15 P50/INTP1/SI00/RxD0/TOOLRxD/SDA00/
TRGIOA HALL U Input
16 P51/INTP2/SO00/TxD0/TOOLTxD/TRGIO
B HALL V Input
17 P17/TI02/TO02/TRDIOA0/TRDCLK0 LED Lighting For lighting
18 P16/TI01/TO01/INTP5/TRDIOC0 Tact Switch Input
19 P15/PCLBUZ1/SCK20/SCL20/TRDIOB0 Drive of U High PWM output
20 P14/RxD2/SI20/SDA20/TRDIOD0 Drive of U Low PWM output
21 P13/TxD2/SO20/TRDIOA1 Drive of V High PWM output
22 P12/SO11/TRDIOB1 Drive of W High PWM output
23 P11/SI11/SDA11//TRDIOC1 Drive of V Low PWM output
24 P10/SCK11/SCL11/TRDIOD1 Drive of W Low PWM output
25 P147/ANI18 AD analog input Speed control
26 P23/ANI3 AD analog input Over-current
protection
27 P22/ANI2 AD analog input Thermal protection
28 P21/ANI1/AVREFM Not used
29 P20/ANI0/AVREFP AD power reference
30 P01/ANI16/TO00/RxD1/TRGCLKB/TRJIO
0 Failure indication Output
31 P00/ANI17/TI00/TxD1/TRGCLKA Tact switch
32 P120/ANI19 Battery check

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 9 of 26
Nov 03,2011
4. Control theory
4.1 Basic control theory of BLDC
The motors used in most power tool are Brushless DC motor, which the rated power is commonly very low. External
rotor structure is usually adopted to drive the power tool directly, but the power is very low because of its low rated
speed. Which cause the motor much bigger than other types of motor which have the same power value.
BLDC motor consists of motor, position sensor and electrical circuit. The stator is often made of several phases (such as
3 phases, four phases and five phases etc.), the rotor is consists of permanent magnet which arranged with different pole
pairs. Figure 4-1 shows a three phases, two poles BLDC motor.
3
2
1
电
源位置
传
感器
电子开关
电机本体
''
Figure 4-1 Structure of three phases, two poles BLDC motor
Three stator coils are connected with correspondent power devices in electrical circuit, A, B, C phase coils each
connected with power switch V1, V2, V3. Position sensors are used to detect the rotor position.
When one of the stator coils are power on, the current will cause torque by the interaction with magnetic field caused by
the rotor permanent magnetism, and the torque will cause the rotor running, the rotor position will be converted to
electrical signal by position sensors to control the electrical switches, thus make the each coils of stator are switched on
sequentially, the stator phase current will also change sequentially according to the position of rotor. Because of the
power on sequence of electrical switches are synchronous with the rotor angle, thus cause the same effect of mechanical
phase change.
Figure 4-2 shows the theory diagram of the half-bridge control of three phases, two poles BLDC motor. Photo-electric
devices are use as the position sensors. The power logic unit consists of three power MOSFET. The control theory will
be discussed below according to the half-bridge control.
Power
Motor
Hall sensors
Electrical switch

RL78/G14 Group Document Name
RESH-OS-MC-20001 Rev.1.00 Page 10 of 26
Nov 03,2011
2
3
1
'
'
电
源
123
Figure 4-2 Three phase brushless motor
The discrepancy of space position of three photo-electrical devices VP1、VP2 and VP3 are 120 degree each. Via the
function of photo-electrical, the rotor position can be achieved.
'
'
'
'
'
'
'
'
a) b) c) d)
Figure 4-3 Commutation sequence and the rotation of magnetic field
The rotor position of figure 4-2 is same as that of figure 4-3a). at this position, the power MOSFET V1 is switched on
and the current flows into coil A-A’, the torque caused by the interaction between the coil current and rotor magnetic
will make the rotor rotate as the direction shown in figure 4-3b). when the rotor locate at the position as in figure 4-
3b), the power MOSFET V1 will be switched off and V2 will be switched on, the current will be changed form coil
A-A’ to B-B’, and the rotor will continue to rotate as the direction shown in figure 4-3b). When the rotor reaches the
position shown as in figure 4-3c), the power MOSFET V2 will be switched off and V3 will be switched on，the
current will be flowed through C-C’，thus the rotor will continue rotate to the position shown in figure 4-3a).
With the change of position sensor signal, the stator coil will be switched on and off sequentially, then the phase
current will be changed sequentially. During the phase change period, the rotating magnetic field generated by the
coils of the stator is not continuous. This kind of rotating magnetic field has three state in 360 degree range, each
state lasts 120 degree. The relationship between each coil and rotor magnetic field are showed in figure 4-3. Figure 4-
3a）is the first state, Fa is the magnetic force generated by coil A-A’, then the interaction between the coil current
and rotor magnetic field will make the rotor rotate clockwise. After 120 degree，the rotor will be in the second state,
the coil A-A’ will be switched off and coil B-B’ will be switched on，the magnetic field generated by stator coil
rotate 120 degree range shown as in figure 4-3b）, and the motor rotor continue to rotate clockwise. After another
Power