ST STM8L-DISCOVERY User manual

September 2010 Doc ID 17693 Rev 1 1/29
UM0970
User Manual
STM8L-DISCOVERY
Introduction
The STM8L-DISCOVERY helps you to discover the STM8L ultralow power features and to
develop and share your applications. It is based on an STM8L152C6T6 and includes an ST-
Link embedded debug tool interface, LCD (24 segments, 4 commons), LEDs and push
buttons.
Figure 1. STM8L-DISCOVERY board
www.st.com
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Contents UM0970
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Contents
1 Quick start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Getting started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Development toolchain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 Demonstration software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Order code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Hardware and layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 STM8L152C6T6 microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Embedded ST-Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.1 Using the ST-Link to program/debug the STM8L on board . . . . . . . . . . 12
3.2.2 Using the ST-Link to program/debug an external STM8L application . . 12
3.3 Power supply and power selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.5 Push buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.6 Built-in IDD measurement circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.6.1 Run mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.6.2 Low power mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.6.3 Low power mode IDD measurement principle . . . . . . . . . . . . . . . . . . . . 15
3.6.4 Ibias current measurement procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.7 Solder bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.8 LCD (24 segments, 4 commons) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4 Extension connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5 Electrical schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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UM0970 Quick start
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1 Quick start
The STM8L-DISCOVERY is a low-cost and easy-to-use development kit to quickly evaluate
and start a development with an STM8L ultralow power microcontroller.
Before installing and using the product, please accept the Evaluation Product License
Agreement from www.st.com/stm8l-discovery.
For more information on the STM8L-DISCOVERY and for demonstration software visit
www.st.com/stm8l-discovery.
1.1 Getting started
1. Check jumper positions on the board, JP1 and CN3 ON (Discovery selected).
2. Connect the STM8L-DISCOVERY board to a PC with a USB cable to power the board.
Red LED LD2 (PWR) then lights up.
3. Function 1 is executed and each click on user button B2 changes the executed function
as described in Ta b l e 1 .
To study or modify the DISCOVER project related to this demo, visit www.st.com/stm8l-
discovery and follow the tutorial. Discover the STM8L features, download and execute
programs proposed in the list of projects. This site also contains examples from which you
can develop your own applications.
1.2 System requirements
●Windows PC (2000, XP, Vista)
●A/Mini-B USB cable
Table 1. Functions
Function LED LD3/4 Bars Value displayed
1 Blink STM8L VDD voltage measured
2 Off STM8L consumption measured in Run mode
3 Off STM8L consumption measured in Low power mode, LCD on
4 Off STM8L consumption measured in Low power mode, LCD off
5 Off STM8L consumption measured in Halt mode, LCD off
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1.3 Development toolchain
●IAR, Embedded Workbench® for STM8
●STMicroelectronics, ST Visual Develop (STVD)
1.4 Demonstration software
Demonstration software is preloaded in the board's Flash memory. This demonstration uses
the built-in IDD measurement feature of the STM8L-DISCOVERY to automatically measure
and display on the LCD the consumption of the MCU in run and low power modes.
The latest versions of this demonstration source code and associated documentation can
be downloaded from www.st.com/stm8l-discovery.
1.5 Order code
To order the STM8L ultralow power Discovery, use the order code STM8L-DISCOVERY.
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UM0970 Features
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2 Features
The STM8L-DISCOVERY offers the following features:
●STM8L152C6T6 microcontroller, 32 KB Flash, 2 KB RAM, 1 KB EEPROM in 48-pin
LQFP
●On-board ST-Link with selection mode switch to use the kit as a stand-alone ST-Link
(with SWIM connector for programming and debugging)
●Two red LEDs; LD1 for USB communication, LD2 for 3.3 V power on
●Designed to be powered by USB or an external supply of 5 V or 3.3 V
●Can supply target application with 5 volts and 3 volts
●Two user LEDs, LD3 and LD4 (green and blue)
●Two push buttons (User and Reset)
●IDD current measurement
●LCD 28-pin DIP (24 segments, 4 commons)
●Extension header for all QFP48 I/Os for quick connection to prototyping board for easy
probing
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Hardware and layout UM0970
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3 Hardware and layout
The STM8L-DISCOVERY is designed around the STM8L152C6T6 microcontroller in a 48-
pin LQFP package.
Figure 2 illustrates the connections between the STM8L152C6T6 and its peripherals (ST-
Link, push button, LED, LCD and connectors).
Figure 3 and Figure 4 help you to locate these features on the STM8L-DISCOVERY.
Figure 2. Hardware block diagram
Blue LED
LD4
B2
USER
I/O
Mini
USB
Green LED
LD3
B1
RST
RESET
I/OI/O
P1 Header
P3Header
P2 Header
SWIM
LCD (24 segments, 4 commons)
IDD
measurement
Embedded
ST-LINK
STM8L152C6T6
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Figure 3. Top layout
ST-Link
LCD 24 segments
IDD measurement
STM8L152C6T6
B2
CN2
JP1
LD3 LD4
B1
CN3
IDD module
LD1
LD2
User button
LED blue
Reset button
LED green
SWIM connector
COM
power
SB1,2
X2 crystal
D2 diode
D1 diode
ST-Link/Discovery
selector
+3.3V power supply
input
+5V
power supply
input
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Figure 4. Bottom layout
P1
P2
SB4,6,8,10
PRG-32
SB3,5,7,9
DEFAULT
SB11,12,14
SB13,15
SB16
SB17
P3
IDD_Measurement
B2-USER
B1-RESET
X3 crystal
connector
connector
connector
JP1
IDD
(RESERVED)
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3.1 STM8L152C6T6 microcontroller
This 8-bit ultralow power MCU has 32 KB Flash, 2 KB RAM, 1 KB data EEPROM, RTC,
LCD, timers, USART, I2C, SPI, ADC, DAC and comparators.
Figure 5. STM8L152C6T6 package
This device provides the following benefits:
●Ultralow power proprietary 130 nm technology:
Speed and power consumption independent of MCU power supply, Ultralow leakage
●Ultralow power design (clock gating, low-power Flash with power-off capability):
Reduced overall Run and Wait mode current consumption by turning off clocks of
unused peripherals or Flash
●Sub 1 µA hardware RTC and AWU system unit:
Ultralow power modes for applications requesting regular wake up
●Range of Low power modes (up to 4):
Suitable for many applications from complete switch off to continuous monitoring at
ultralow frequency
●Advanced and flexible clock system (multiple internal and external clock sources):
Switch and adjust frequency and clock sources on the fly depending on application
needs
●Direct memory access on board (4-channel DMA):
Autonomy for peripherals, independent from core; can switch off Flash memory and
CPU (large current consumption contributors) while keeping peripherals active
●Ultralow power and ultrasafe reset system POR/PDR; additional optional activation
BOR:
Integrated safety and security for application
●Ultrafast wakeup from lowest Low power mode (4 µs):
Fast switching from Static and Dynamic power modes
●Analog functional down to 1.8 V, programming down to 1.65 V:
Full functionality over the complete VDD range
For more information see the STM8L152C6T6 datasheet (Doc ID 15962) on the ST website.
The STM8L152C6T6 8-bit microcontroller offers:
2 Kbytes RAM
32 Kbytes of Flash memory
LQFP48 7 x 7 mm
1 Kbytes EEPROM
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Hardware and layout UM0970
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Figure 6. STM8L152C6T6 block diagram
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3.2 Embedded ST-Link
The ST-Link programming and debugging tool is integrated on the STM8L-DISCOVERY.
The embedded ST-Link can be used in 2 different ways according to the jumper states (see
Ta bl e 2 ):
●to program/debug the MCU on board,
●to program/debug an MCU in an external application board using a cable connected to
SWIM connector CN2.
For information about debugging and programming features refer to ST-Link UM0627.
Note: UM0627 contains information about all the ST-Link features. Usage in this situation is
restricted to STM8 devices and SWIM support.
Figure 7. Typical configuration
Table 2. Jumper states
Jumper state Description
Both CN3 jumpers ON ST-Link functions enabled for on board programming (default)
Both CN3 jumpers OFF ST-Link functions enabled for external application through CN2
connector (SWIM supported).
Hardware requirements:
- USB cable type A to mini-B
- Computer with Windows 2000, XP or Vista OS
Development toolchain:
- IAR, Embedded Workbench® for STM8L
- STMicroelectronics, ST Visual Develop (STVD)
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3.2.1 Using the ST-Link to program/debug the STM8L on board
To program the STM8L on board, simply plug in the two jumpers on CN3, as shown in
Figure 8 in red, but do not use the CN2 connector as that could disturb communication with
the STM8L152C6T6 of the STM8L-DISCOVERY.
Figure 8. STM8L-DISCOVERY connections image
3.2.2 Using the ST-Link to program/debug an external STM8L application
It is very easy to use the ST-Link to program the STM8L on an external application. Simply
remove the 2 jumpers from CN3 as shown in Figure 9, and connect your application to the
CN2 debug connector according to Ta b l e 3 .
Jumpers on CN3
Table 3. Debug connector CN2 (SWIM)
Pin CN2 Designation
1 VDD_TARGET VDD from application
2 SWIM SWIM data input/output
3 GND Ground
4 SWIM_RST SWIM reset
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Figure 9. ST-Link connections image
3.3 Power supply and power selection
The power supply is provided either by the host PC through the USB cable, or by external
power supply (5 V or 3.3 V). The D1 and D2 protection diodes allow the 5V and 3V3 pins to
be used independently as input or output power supplies (see Figure 3). The 5V and 3V3
pins can be used as an output power supply for use by an application board connected on
pin headers (P1 to P3). In such a case, the 3V3 pin provides only a 3V power supply and the
power consumption must be lower than 100 mA. The 5V and 3V3 pins can also be used as
an input power supply for the board when the USB connector is not connected to the PC.
3.4 LEDs
●LD1 COM: Red LED indicates communication in progress between PC and ST-Link.
●LD2 PWR: Red LED indicates that the board is powered.
●LD3 PE7: Green LED is a user LED connected to the I/O PE7 of the STM8L152C6T6.
●LD4 PC7: Blue LED is a user LED connected to the I/O PC7 of the STM8L152C6T6.
3.5 Push buttons
●B1 RST: Push button is used to RESET the STM8L152C6T6.
●B2 USER: User push button connected to the I/O PC1 of the STM8L152C6T6.
No jumpers on CN3
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3.6 Built-in IDD measurement circuit
The STM8L-DISCOVERY built-in IDD measurement circuit allows the consumption of the
STM8L152C6T6 to be measured and displayed on the LCD Glass while the MCU is in Run
or Low power saving modes.
●JP1 in ON position: STM8L152C6T6 is powered through IDD measurement circuit
(default).
●JP1 in OFF position: STM8L152C6T6 is powered directly by +3V3, IDD measurement
circuit is bypassed.
Note: When jumper JP1 is removed the current consumption of the STM8L152C6T6 can be
measured by connecting an ammeter between jumper JP1 pin 1 and pin 2.
For IDD measurement by the MCU itself, the circuit below is implemented on the STM8L-
DISCOVERY. Solder bridges SB11, SB12 and SB14 must be closed and a jumper must be
plugged between JP1 pin 2 and pin 3.
Figure 10. STM8L-DISCOVERY IDD measurement circuit
3.6.1 Run mode
In Run mode, IDD current is measured using the operational amplifier MAX9938FEUK+ (U4)
connected to the 2Ωshunt resistor (R20). In this case IDD_CNT_EN remains high during
measurement, so R21 remains in short-circuit during the measurement because of transitor
T1 which remains ON permanently. The jumper JP1 must be connected between pins 2 and
3 of JP1.
3.6.2 Low power mode
In Low power modes (Halt or Active halt), the operational amplifier MAX9938FEUK+ (U4) is
connected to the 2KΩshunt resistor (R21), controlled by the analogue switch STT5PF20V
(T1). In this case the counter 74HC4060 (U3) enabled by IDD_CNT_EN manages the
measurement timing according to Figure 11.
R19
47K
IDD_Measurement
IDD_CNT_EN
IDD_WAKEUP
2
3
4
5
U7
74LX1G04CTR
I/O
1O/I 2
GND
3C
4
VCC 5
U6
74H1G66STR
+3V3 R20
2(1%)
R21
2K(1%)
3
4 5
G
SD
1 2 6
T1
STT5PF20V
3
4
5
G
S
D
1
2
6
T2
STT5PF20V
+3V3
Q12
1
Q13
2
Q14
3
Q6
4
Q5
5
Q7
6
Q4
7
GND
8CO 9
CO 10
CI 11
CLR 12
Q9 13
Q8 14
Q10 15
VCC 16
U3
M74HC4060TTR
+3V3
+3V3
R26
10K
R18
10K C11
1uF +3V3
VDD_MCU
1
2
3
JP1
C13
1nF
R22
15K
R23
30K
Oscillator frequency 30KHz
+3V3
R17
0
PF0
PE6
PC4
C12
100nF
4
5
2
3
1
U4
MAX9938FEUK+
SB11
SB12
SB14
IDD
onoff
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3.6.3 Low power mode IDD measurement principle
The principle used to measure a current when the STM8L152C6T6 is in Low power mode is:
1. Configure ADC to measure voltage on the IDD_Measurement pin.
2. Configure PE6 to serve as wakeup pin.
3. Enter Low power mode after setting IDD_CNT_EN (PC4) signal low.
4. IDD_WAKEUP rising edge wakes up the MCU after around 300 ms.
5. Start ADC conversion as soon as possible after wakeup in order to measure the
voltage corresponding to Low power mode on capacitor C11.
6. Reset the counter by programming IDD_CNT_EN high (in less than 70 ms after the
wakeup) to avoid the R21 2 KΩresistor being connected later in Run mode.
The measurement timing is given in Figure 11. In Low power modes, the 2 KΩresistor is
connected when T1 goes off after entering Low power mode. Q13 output of the counter
allows connection of the 2 KΩ resistor when the current IDD becomes very low.
Figure 11 shows how the counter and T1 ensure that, 150 ms after IDD_CNT_EN falling
edge, the shunt resistor R21 is connected between VDD_MCU and the power supply in
order to reduce the measurement range to 30 uA full scale. Then after another 150 ms for
current stabilization, R21 is shorted, the IDD measurement is stored in C11, and the MCU is
woken up. After wakeup the MCU can measure the IDD current corresponding to the Low
power mode stored in C11.
Figure 11. STM8L-DISCOVERY IDD Low power mode measurement timing diagram
The Low power mode measurement procedure can be used in Halt or Active halt mode if the
IDD current does not exceed 30 uA, otherwise the IDD measurement procedure in Run mode
should be used up to 30 mA.
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3.6.4 Ibias current measurement procedure
In Low power mode the bias current of operational amplifier input (U4 pin 4) is not negligible
compared to IDD current (typical Ibias is ~240 nA). To obtain a reliable STM8L152 IDD
measurement it is mandatory to subtract the bias current from the IDD low power
measurement since this current is not sinked by the MCU. Ibias is measured during
production test and stored in the MCU EPROM. The demonstration software, Discover, uses
this value to display the correct IDD. The Ibias measurement procedure is part of the
demonstration software and can be launched if required.
The procedure for Ibias measurement (implemented in the Demo) is:
1. Power off the board (disconnect the USB cable).
2. Set jumper JP1 to OFF position (pins 1 and 2).
3. Push down B2 (USER button), power on the board from the USB.
4. Wait at least 1 second before releasing B2, the LCD displays the Ibias measurement.
5. Power off the board (disconnect the USB cable).
6. Set jumper JP1 to ON position (pins 2 and 3). The Ibias value is now stored. The bias
current is then subtracted from the IDD measurement performed in Low power mode.
3.7 Solder bridges
Table 4. Solder bridge
Bridge State(1)
1. Default state is in bold type.
Description
SB1,2
(X2 crystal)
Off PA2, PA3 are disconnected from P1
X2, C19, C20 and R24 provide a clock as shown in schematics
On PA2, PA3 are connected to P1 (X2, C19, C20, R24 must not be fitted)
SB3,5,7,9
(DEFAULT) On Reserved, do not modify
SB4,6,8,10
(PRG-32) Off Reserved, do not modify
SB11,12,14
(IDD_Measurement)
Off PFO, PE6, PC4 are available and IDD module cannot be used
JP1 must be set to OFF
On PFO, PE6, PC4 are used by IDD module
JP1 must be set to ON
SB13,15
(X3 crystal)
Off PC5, PC6 are only connected to P2 (but do not remove X3, C21, C23, R27)
On PC5, PC6 are connected to P2. X3, C21, C23 and R27 provide 32 KHz clock
SB16
(B1-RESET)
Off PA1/RESET signal is only connected to P1
On PA1/RESET signal is used by ST_LINK as SWIM_RST and also connected to P1
SB17
(B2-USER)
Off PC1 is only connected to P2
On PC1 is connected to P2 and push button B2 for user
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3.8 LCD (24 segments, 4 commons)
This LCD allows the STM8L152C6T6 to display any information on six 14-segment digits
and 4 BARs, using all COMs. (See the LCD segment mapping in Figure 12 and pin
connections in Ta bl e 5 .)
Note: This LCD also supports six 8-segment digits by only using COM0 and COM1.
This configuration allows COM2 and COM3 to be used as I/O ports. In this case the 2 LCD
pins must not be plugged into the LCD socket. To proceed with this configuration, remove
the LCD carefully, slightly open the COM2 and COM3 pins (pin 13 and pin 14) of the LCD,
then replug it in the socket.
Characteristics overview:
●24 segments and 4 commons
●Drive method: multiplexed 1/4 duty, 1/3 bias
●Operating voltage: 3 V
●Operating temperature: 0 to 50°C
●Connector: 28-pin DIL 2.54 mm pitch
Note: When the LCD is plugged, all I/O ports listed in Tabl e 5 are unavailable. To use one of these
as I/O, you must remove the LCD.
Figure 12. LCD segment mapping
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Table 5. LCD connections
STM8L152C6T6 LCD
Pin name Pin COM3 COM2 COM1 COM0
PA7_LCDSEG0 1 1N 1P 1D 1E
PE0_LCDSEG1 2 1DP 1COLON 1C 1M
PE1_LCDSEG2 3 2N 2P 2D 2E
PE2_LCDSEG3 4 2DP 2COLON 2C 2M
PE3_LCDSEG4 5 3N 3P 3D 3E
PE4_LCDSEG5 6 3DP 3COLON 3C 3M
PE5_LCDSEG6 7 4N 4P 4D 4E
PD0_LCDSEG7 8 4DP 4COLON 4C 4M
PD2_LCDSEG8 9 5N 5P 5D 5E
PD3_LCDSEG9 10 BAR2 BAR3 5C 5M
PB0_LCDSEG10 11 6N 6P 6D 6E
PB1_LCDSEG11 12 BAR0 BAR1 6C 6M
PD1_LCDCOM3 13 COM3
PA6_LCDCOM2 14 COM2
PA5_LCDCOM1 15 COM1
PA4_LCDCOM0 16 COM0
PB2_LCDSEG12 17 6J 6K 6A 6B
PB3_LCDSEG13 18 6H 6Q 6F 6G
PB4_LCDSEG14 19 5J 5K 5A 5B
PB5_LCDSEG15 20 5H 5Q 5F 5G
PB6_LCDSEG16 21 4J 4K 4A 4B
PB7_LCDSEG17 22 4H 4Q 4F 4G
PD4_LCDSEG18 23 3J 3K 3A 3B
PD5_LCDSEG19 24 3H 3Q 3F 3G
PD6_LCDSEG20 25 2J 2K 2A 2B
PD7_LCDSEG21 26 2H 2Q 2F 2G
PC2_LCDSEG22 27 1J 1K 1A 1B
PC3_LCDSEG23 28 1H 1Q 1F 1G
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Extension connection UM0970
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4 Extension connection
Male headers P1, P2 and P3 can connect the STM8L-DISCOVERY to a standard
prototyping/wrapping board. All GPI/Os of STM8L152C6T6 are available on it.
P1, P2 and P3 can also be probed by an oscilloscope, logical analyzer or voltmeter.
Table 6. P1 pinout
Pin number
(P1)
Pin number
(STM8L)
Board pin
name
Type
Main
function Alternate function LCD (U5)
1+3V3
3.3 V board power
supplied or supply
external application when
USB connected
2 1 PA0 I/O Port A0
PA0/[USART1_CK](3)/
SWIM/BEEP/
IR_TIM (7)
3 9/40 GND Ground
4 2 PA1 I/O Reset NRST/PA1(1)
5 3 PA2 I/O Port A2
PA 2 / O S C _ I N /
[USART1_TX](3)/
[SPI1_MISO] (3)
6 4 PA3 I/O Port A3
PA 3 / O S C _ O U T /
[USART1 _RX](3)/
[SPI1_MOSI](3)
7 5 PA4 I/O Port A4
PA4/TIM2_BKIN/
LCD_COM0(2)/
ADC1_IN2/
COMP1_INP
LCD_COM0
8 6 PA5 I/O Port A5
PA5/TIM3_BKIN/
LCD_COM1(2)/
ADC1_IN1/
COMP1_INP
LCD_COM1
9 7 PA6 I/O Port A6
PA6/[ADC1_TRIG](3)/
LCD_COM2(2)/
ADC1_IN0/
COMP1_INP
LCD_COM2
10 8 PA7 I/O Port A7 PA 7 /
LCD_SEG0(2)(4) LCD_SEG0
11 14 PE0 I/O Port E0 PE0(4)/
LCD_SEG1(2) LCD_SEG1
12 15 PE1 I/O Port E1 PE1/TIM1_CH2N /
LCD_SEG2(2) LCD_SEG2
13 16 PE2 I/O Port E2 PE2/TIM1_CH3N /
LCD_SEG3(2) LCD_SEG3
14 17 PE3 I/O Port E3 PE3/LCD_SEG4(2) LCD_SEG4
15 18 PE4 I/O Port E4 PE4/LCD_SEG5(2) LCD_SEG5
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UM0970 Extension connection
Doc ID 17693 Rev 1 20/29
16 19 PE5 I/O Port E5
PE5/LCD_SEG6(2)/
ADC1_IN23/
COMP2_INP/
COMP1_INP
LCD_SEG6
17 20 PD0 I/O Port D0
PD0/TIM3_CH2/
[ADC1_TRIG](3)/
LCD_SEG7(2)/
ADC1_IN2 2/
COMP2_INP/
COMP1_INP
LCD_SEG7
18 21 PD1 I/O Port D1
PD1/TIM3_TRIG/
LCD_COM3(2)/
ADC1_IN21/
COMP2_INP/
COMP1_INP
LCD_COM3
19 9/40 GND Ground
Table 7. P2 pinout
Pin number
(P2)
Pin number
(STM8L) Pin name
Type
Main
function Alternate function LCD (U5)
1+5V
5 Volts board power
supplied or supply
external application when
USB connected
2 NC
3 9/40 GND Ground
4 48 PE7 I/O Port E7 PE7/LCD_SEG27(2)
5 47 PE6 I/O Port E6
PE6/LCD_SEG26(2)/
PVD_IN
6 46 PC7 I/O Port C7
PC7/LCD_SEG25(2)/
ADC1_IN3/
COMP2_INM/
COMP1_INP
7 45 PC6 I/O Port C6
PC6/OSC32_OUT/
[SPI1_SCK](3)/
[USART1_RX](3)
8 44 PC5 I/O Port C5
PC5/OSC32_IN /
[SPI1_NSS](3)/
[USART1_TX](3)
9 43 PC4 I/O Port C4
PC4/[USART1_CK](3)/
I2C1_SMB/CCO/
LCD_SEG24(2)/
ADC1_IN4/COMP2_INM/
COMP1_INP
Table 6. P1 pinout (continued)
Pin number
(P1)
Pin number
(STM8L)
Board pin
name
Type
Main
function Alternate function LCD (U5)
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