STMicroelectronics 32L4R9IDISCOVERY User manual

October 2017 DocID030906 Rev 2 1/78
1
UM2271
User manual
Discovery kit with STM32L4R9AI MCU
Introduction
The 32L4R9IDISCOVERY kit is a complete demonstration and development platform for the
STMicroelectronics Arm®Cortex®-M4 core-based STM32L4R9AI microcontroller.
Leveraging the innovative ultra-low power oriented features, 640 Kbytes of embedded RAM,
graphics performance (Chrom-ART Accelerator™) and DSI controller offered by the
STM32L4R9AI, the 32L4R9IDISCOVERY kit enables users to easily prototype applications
with state-of-the-art energy efficiency, as well as providing stunning audio and graphics
rendering with direct support for an AMOLED DSI round display. For even more user-
friendliness, the on-board ST-LINK/V2-1 debugger provides out-of-the-box programming
and debugging capabilities.
The STM32L4R9AI microcontroller features four I2Cs, five USARTs, one ULP UART, three
SPIs, two SAIs, one SDIO, one USB 2.0 full-speed OTG, two CANs, one FMC parallel
synchronous interface, one 12-bit ADC, one 12-bit DAC, two ULP analog comparators, two
op amps, one 2 data-lane DSI display, one digital filter for sigma delta modulator and SWP
interface, two Octo-SPI interfaces, 8- to 14-bit camera interface, one touch sensing
controller interface, JTAG and SWD debugging support.
This Discovery board offers everything required for users to get started quickly and develop
applications easily.The hardware features on the board help to evaluate the following
peripherals: USB OTG FS, microSD™ card, 8-bit camera interface, 16-Mbit PSRAM, PMOD
and STMod+ connectors, IDD measurement, full-duplex I2S with an audio codec and stereo
headset jack including an analog microphone, DFSDM with a pair of MEMS digital
microphones on board, 512-Mbit Octo-SPI Flash memory device, I2C extension connector,
1.2" AMOLED display using a one data-lane DSI interface with a capacitive touch panel.
The Arduino™ compatible connectors expand the functionality with a wide choice of
specialized shields. The integrated ST-LINK/V2-1 provides an embedded in-circuit
debugger and programmer for the STM32 MCU.
Pictures are not contractual
Figure 1. 32L4R9IDISCOVERY top view Figure 2. 32L4R9IDISCOVERY bottom view
www.st.com

Contents UM2271
2/78 DocID030906 Rev 2
Contents
1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 Product marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Development toolchains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Demonstration software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7 Technology partners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8 Bootloader limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9 AMOLED display limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10 Hardware layout and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10.1 32L4R9IDISCOVERY layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
10.2 32L4R9IDISCOVERY mechanical drawing . . . . . . . . . . . . . . . . . . . . . . . 15
10.3 Embedded ST_LINK/V2-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.3.1 Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.3.2 ST-LINK/V2-1 firmware upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.4 Low-power consumption status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.5 TAG and SWD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10.6 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.6.1 Power supply sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.6.2 MCU power supply options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.6.3 Supplying 32L4R9IDISCOVERY through ST-LINK/V2-1 USB . . . . . . . . 21
10.6.4 Measurement of MCU current consumption . . . . . . . . . . . . . . . . . . . . . 22
10.6.5 Program or debug when power supply not from ST-LINK/V2-1 . . . . . . . 23
10.7 Clock sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
10.8 Reset Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

DocID030906 Rev 2 3/78
UM2271 Contents
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10.9 Boot configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.10 Audio codec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.11 DFSDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.12 PSRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.13 USB OTG FS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.13.1 32L4R9IDISCOVERY as USB device . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.13.2 32L4R9IDISCOVERY as USB host . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10.14 Octo-SPI Flash memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10.15 Virtual COM port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10.16 Buttons and LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
11.1 Arduino connectors CN10, CN11, CN16 and CN17 . . . . . . . . . . . . . . . . . 28
11.2 DSI display, backlight and touch panel connector CN4 . . . . . . . . . . . . . . 30
11.2.1 DSI AMOLED display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
11.2.2 Backlight and OLED power supplies generation . . . . . . . . . . . . . . . . . . 32
11.2.3 Touch panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
11.3 USB OTG FS connector CN9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
11.4 ST-LINK/V2-1 USB Micro-B connector CN13 . . . . . . . . . . . . . . . . . . . . . 33
11.5 microSD card connector CN6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.6 STMod+ connector CN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
11.7 PMOD connector CN3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
11.8 Camera module connector CN2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
11.9 TAG connector CN8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.10 SWD header CN5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.11 EXT_I2C connector CN7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
11.12 Stereo headset and headphone jack CN12 . . . . . . . . . . . . . . . . . . . . . . . 41
Appendix A GPIO assignment and sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Appendix B Solder bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Appendix C STMod+ GPIO sharing and multiplexing . . . . . . . . . . . . . . . . . . . . . 52
Appendix D Schematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Contents UM2271
4/78 DocID030906 Rev 2
Appendix E Fanout board (MB1280) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
E.1 MikroElektronika mikroBUS™ compatible connector
(Fanout CN10 / CN11). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
E.2 ESP-01 Wi-Fi®board compatible connector . . . . . . . . . . . . . . . . . . . . . . . 72
E.3 Compatible connectors for the Grove boards . . . . . . . . . . . . . . . . . . . . . . 72
E.3.1 Compatible connector for I2C Grove boards (Fanout CN3) . . . . . . . . . . 72
E.3.2 Compatible connector for UART Grove boards (Fanout CN2) . . . . . . . . 73
Appendix F Federal Communications Commission (FCC) and Industry Canada
(IC) Compliance74
F.1 FCC Compliance Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F.1.1 Part 15.19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F.1.2 Part 15.105 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F.1.3 Part 15.21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F.2 IC Compliance Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F.2.1 Compliance Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
F.2.2 Déclaration de conformité. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Appendix G CISPR32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
G.1 Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

DocID030906 Rev 2 5/78
UM2271 List of tables
5
List of tables
Table 1. Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Table 2. JP10: VDD_STL setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 3. SW1 switch setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 4. 32L4R9IDISCOVERY power sources configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 5. JP4: power source selector setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 6. JP5: ARD 5 V input/output voltage selection setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 7. JP7: VDD setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 8. JP1: IDD_MCU measurement setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 9. JP3: VDDA and VDDUSB, settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 10. Boot modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 11. LD1 and LD2 details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 12. Buttons and LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 13. Arduino compatible connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 14. JP3, VDDA and VDDUSB, settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 15. DSI display connector CN4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 16. USB OTG FS Micro-AB connector CN9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 17. USB Micro-B connector CN13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 18. microSD connector CN6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 19. STMod+ connector CN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 20. Quad SPDT switch configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 21. PMOD connector CN3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 22. Camera module connector CN2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 23. TAG connector CN8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 24. SWD header CN5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 25. EXT_I2C connector CN7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 26. I2C1 addresses (on board) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 27. Audio jack connector CN12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Table 28. 32L4R9IDISCOVERY GPIO assignment and sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 29. MFX_V3 GPIO assignment (LQFP48) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 30. 32L4R9IDISCOVERY solder bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Table 31. STMod+ GPIO sharing and multiplexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Table 32. SPDT quad switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Table 33. Description of the mikroBUS connectors (CN11 and CN10) . . . . . . . . . . . . . . . . . . . . . . . 72
Table 34. Description of the ESP-01 Wi-Fi board connector pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Table 35. Description of the I2C Grove board connector pins (CN3) . . . . . . . . . . . . . . . . . . . . . . . . . 73
Table 36. Description of the UART Grove board connector pins (CN2) . . . . . . . . . . . . . . . . . . . . . . . 73
Table 37. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

List of figures UM2271
6/78 DocID030906 Rev 2
List of figures
Figure 1. 32L4R9IDISCOVERY top view. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. 32L4R9IDISCOVERY bottom view. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 3. Hardware block diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 4. 32L4R9IDISCOVERY top side layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 5. 32L4R9IDISCOVERY bottom side layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 6. 32L4R9IDISCOVERY mechanical drawing (top view, in mm) . . . . . . . . . . . . . . . . . . . . . . 15
Figure 7. 32L4R9IDISCOVERY mechanical drawing (bottom view, in mm) . . . . . . . . . . . . . . . . . . . 16
Figure 8. How to update driver software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 9. JP4 default configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 10. DSI display connector CN4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 11. USB OTG FS Micro-AB connector CN9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 12. USB Micro-B connector CN13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 13. microSD connector CN6 (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 14. STMod+ connector CN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 15. PMOD connector CN3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 16. Camera module connector CN2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 17. TAG connector CN8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 18. EXT_I2C connector CN7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figure 19. Stereo headset with microphone jack CN12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 20. 32L4R9IDISCOVERY board interconnections (MB1311C) . . . . . . . . . . . . . . . . . . . . . . . . 55
Figure 21. 32L4R9IDISCOVERY power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Figure 22. 32L4R9IDISCOVERY Arduino Uno V3 connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Figure 23. 32L4R9IDISCOVERY ST-LINK/V2-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Figure 24. 32L4R9IDISCOVERY Octo-SPI Flash memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Figure 25. 32L4R9IDISCOVERY peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Figure 26. 32L4R9IDISCOVERY USB OTG FS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Figure 27. 32L4R9IDISCOVERY Round DSI display interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Figure 28. 32L4R9IDISCOVERY IDD measurement and Multi Function eXpander . . . . . . . . . . . . . . 63
Figure 29. 32L4R9IDISCOVERY microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Figure 30. 32L4R9IDISCOVERY PSRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Figure 31. 32L4R9IDISCOVERY camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figure 32. 32L4R9IDISCOVERY STMOD+ interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Figure 33. 32L4R9IDISCOVERY Audio and DFSDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Figure 34. Round DSI display board (MB1314) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Figure 35. Fanout board (MB1280) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Figure 36. STMod+ Fanout module plugged into CN1 connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

DocID030906 Rev 2 7/78
UM2271 Features
77
1 Features
•STM32L4R9AI Arm-based microcontroller with 2-Mbyte Flash memory and 640-Kbyte
RAM in UFBGA169 package
•1.2" 390x390 pixel AMOLED round display panel with 16 million colors depth, MIPI®DSI
interface and capacitive touch panel
•USB OTG FS
•On-board current measurement
•SAI audio codec
•ST-MEMS digital microphones
•16-Mbit asynchronous PSRAM
•512-Mbit Octo-SPI Flash
•2 user LEDs
•1 reset push-button
•4-direction joystick with selection button
•Board connectors:
– 8-bit camera
– USB OTG FS with Micro-AB
– Stereo headset jack including analog microphone input
– microSD card
•Board expansion connectors:
– Arduino Uno V3
–STMod+
–PMOD
– EXT_I2C
•Flexible power-supply options:
–ST-LINKUSBV
BUS or external sources
•On-board ST-LINK/V2-1 debugger/programmer with USB
re-enumeration capability: mass storage, virtual COM port and debug port
•Comprehensive free software libraries and examples available with the STM32Cube
package
•Support of a wide choice of integrated development environments (IDEs), including
IAR™, Keil®and GCC-based IDEs
2 Product marking
Evaluation tools marked as “ES” or “E” are not yet qualified and are therefore not ready to
be used as reference design or in production. Any consequences arising from such usage

System requirements UM2271
8/78 DocID030906 Rev 2
will not be at ST’s charge. In no event will ST be liable for any customer usage of these
engineering sample tools as reference designs or in production.
‘E’ or ‘ES’ marking examples of location:
•on the targeted STM32 that is soldered on the board (for illustration of STM32 marking,
refer to the section ‘Package information’ of the STM32 datasheet at www.st.com).
•next to the evaluation tool ordering part number, that is stuck or silkscreen printed on
the board
This board features a specific STM32 device version which allows the operation of any
stack or library. This STM32 device shows a "U" marking option at the end of the standard
part number and is not available for sales.
3 System requirements
•Windows®OS (7, 8 and 10), Linux®64-bit or macOS®
•USB Type-A to Micro-B cable
4 Development toolchains
•Keil MDK-ARM(a)
•IAR EWARM(a)
•GCC-based IDEs including free SW4STM32 from AC6
5 Demonstration software
The demonstration software, included in the STM32Cube package corresponding to the on-
board MCU, is preloaded in the STM32 Flash memory for easy demonstration of the device
peripherals in standalone mode. The latest versions of the demonstration source code and
associated documentation can be downloaded from the www.st.com/stm32l4-discovery web
page.
6 Ordering information
To order the 32L4R9IDISCOVERY kit, refer to Table 1.
a. On Windows only

DocID030906 Rev 2 9/78
UM2271 Technology partners
77
7 Technology partners
MACRONIX:
512-Mbit Octo-SPI NOR Flash memory device, part number MX25LM51245GXDI00
GOVISIONOX OPTOELECTRONICS:
1.2 inch 390x390 AMOLED display, part number G1120TB103GF-001
Table 1. Ordering information
Order code Target STM32
STM32L4R9I-DISCO STM32L4R9AII6

Bootloader limitations UM2271
10/78 DocID030906 Rev 2
8 Bootloader limitations
Boot from system Flash memory results in executing bootloader code stored in the system
Flash memory protected against writing and erasing. This allows in-system programming
(ISP), that is, flashing the STM32 user Flash memory. It also allows writing data into RAM.
The data come in via one of communication interfaces such as USART, SPI, I2C bus, USB
or CAN.
Bootloader version is identified by reading the bootloader ID at the address 0x1FFF6FFE.
Its value is 0x91 for bootloader V9.1 and 0x92 for V9.2.
The STM32L4R9AII6 part soldered on the 32L4R9IDISCOVERY main board is marked with
a date code corresponding to its date of manufacturing. STM32L4R9AII6 parts with a date
code prior or equal to week 37 of 2017 are fitted with bootloader V9.1 affected by the
limitations to be worked around, as described hereunder. Parts with the date code starting
from week 38 of 2017 contain bootloader V9.2 in which the limitations no longer exist.
To locate the visual date code information on the STM32L4R9II6 package, refer to its
datasheet (DS12023) available at www.st.com, section Package Information. Date code
related portion of the package marking takes Y WW format, where Y is the last digit of the
year and WW is the week. For example, a part manufactured in week 38 of 2017 bares the
date code 7 38.
There is also another mean to identify the need for workaround: before opening the blister of
the Discovery Kit, just check the back side of the blister. At the bottom left side, if the
reference number is equal or higher than 32L4R9IDISCO/ 02-0, it means the bootloader
version is V9.2 and there is no need to apply workaround. Any other inferior number like 01-
0 will need the workaround.
Bootloader ID for the bootloader V9.1 is 0x91.
The following limitation exists in the bootloader V9.1:
Some user Flash memory data get corrupted when written via SPI interface
Description:
During bootloader SPI Write Flash operation, some random 64-bits (2 double-words) may
be left blank at 0xFF
Workarounds:
WA1: add a delay between sending Write command and its ACK request. Its duration
should be the duration of the 256-Byte Flash write time.
WA2: read back after each write operation (256 bytes or at end of user code flashing) and in
case of error start write again.
WA3: Using bootloader, load a patch code in RAM to write in Flash memory through same
Write Memory write protocol as bootloader (code provided by ST). The patch code is
available for download from www.st.com website with a readme.txt file containing usage
instructions.

DocID030906 Rev 2 11/78
UM2271 AMOLED display limitation
77
9 AMOLED display limitation
Warning: Permanent image sticking may occur if AMOLED displays
same image for an extended period of time.
10 Hardware layout and configuration
32L4R9IDISCOVERY board is designed around the STM32L4R9AI (169 ball UFBGA
package DSI version). The hardware block diagram Figure 3 illustrates the connection
between STM32L4R9AI and peripherals (PSRAM, Octo-SPI Flash, DSI color display, USB
OTG connector, USART, audio, camera connector, STMod+ and PMOD connectors, IDD
measurement, joystick, microSD card, I2C extension connector, Arduino Uno shields and
embedded ST-LINK). Figure 4 and Figure 5 help the user to locate these features on the
board. Mechanical drawing for 32L4R9IDISCOVERY and round DSI display boards is
described in Figure 6.

Hardware layout and configuration UM2271
12/78 DocID030906 Rev 2
Figure 3. Hardware block diagram
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DocID030906 Rev 2 13/78
UM2271 Hardware layout and configuration
77
10.1 32L4R9IDISCOVERY layout
Figure 4. 32L4R9IDISCOVERY top side layout
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Hardware layout and configuration UM2271
14/78 DocID030906 Rev 2
Figure 5. 32L4R9IDISCOVERY bottom side layout
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DocID030906 Rev 2 15/78
UM2271 Hardware layout and configuration
77
10.2 32L4R9IDISCOVERY mechanical drawing
Figure 6. 32L4R9IDISCOVERY mechanical drawing (top view, in mm)
Legend:
= Indicates the mounting hole between the 32L4R9IDISCOVERY board (at the top of Figure 6) and
the round DSI display board (at the bottom of Figure 6)

Hardware layout and configuration UM2271
16/78 DocID030906 Rev 2
Figure 7. 32L4R9IDISCOVERY mechanical drawing (bottom view, in mm)
Plastic spacer height = 13 mm, overall height = 26 mm ± 1 mm
10.3 Embedded ST_LINK/V2-1
The ST-LINK/V2-1 programming and debugging tool is integrated on the
32L4R9IDISCOVERY board. Compared to ST-LINK/V2, the changes are listed below:
•new features supported on ST-LINK/V2-1:
– USB software re-enumeration
– Virtual Com port interface on USB
– Mass storage interface on USB
– USB power management request for more than 100 mA power on USB
•features no more supported on ST-LINK/V2-1:
–SWIMinterface
– Application voltage lower than 3 V
For general information concerning the debugging and programming features that are
common to both versions V2 and V2-1, refer to ST-LINK/V2 in-circuit
debugger/programmer.

DocID030906 Rev 2 17/78
UM2271 Hardware layout and configuration
77
10.3.1 Drivers
Before connecting the 32L4R9IDISCOVERY to a Windows (7, 8, 10) PC via USB, a driver
for ST-LINK/V2-1 must be installed. It is available on the www.st.com website.
If 32L4R9IDISCOVERY is connected to the PC before the driver is installed, some
interfaces of the board may be declared as ‘Unknown’ in the PC device manager. In this
case the user must install the driver files, and update the driver of the connected device
from the device manager as shown on Figure 8: How to update driver software
Note: Prefer using the ‘USB Composite Device’ handle for a full recovery.
Figure 8. How to update driver software
10.3.2 ST-LINK/V2-1 firmware upgrade
The ST-LINK/V2-1 embeds a firmware upgrade mechanism for in-situ upgrade through the
USB port. As the firmware may evolve during the life time of the ST-LINK/V2-1 product
(such as new functionality, bug fixes or support for new microcontroller families), it is
recommended to visit www.st.com before starting to use the 32L4R9IDISCOVERY and
periodically, in order to stay up-to-date with the latest firmware version.
10.4 Low-power consumption status
There is a way to make the board get into very low power consumption status in which the
current on +5 V can be below 20 uA. How to get into the low power mode:
1. The connections between ST-LINK/V2-1 and MCU must be disconnected by micro
switch SW1 manually (see Table 3 below). Set JP4 on (7) ARD position, and put JP5 in
ARD-5V IN position. Remove JP10. Then, connect an external 5 V power supply on
CN16 pin 5 5V and on GND.
2. Peripherals (including display, CTP and PSRAM) are powered off by MOSFET which is
controlled by MFX_GPIO8 / MFX_aGPIO2 (put them as input floating), and by setting

Hardware layout and configuration UM2271
18/78 DocID030906 Rev 2
all peripherals related I/Os to inactive level (input pull-down or input is good option
according to I/Os).
3. Disconnect JP9 to remove +5 V from LD8 power LED, disconnect JP10 (or put it in 2-3
position), power off OCTOSPI (remove SB23/SB24) and configure related I/Os as input
pull down.
4. Peripherals can be setup by FW to reach power down mode. All I/Os must be
configured in non-consuming states. Set MFX_V3 to sleep mode, get SD card out of its
socket slot. Set the Audio Codec in power down.
10.5 TAG and SWD
One TAG interface footprint CN8 is reserved on 32L4R9IDISCOVERY and is usable to
debug and program the on-board MCU.
Note: Micro switch SW1 must be put in Off position. R24 and R31 must be disconnected.
The SWD 6-pin header CN5 added on 32L4R9IDISCOVERY, connected to on board ST-
LINK MCU, is usable to debug and program an external MCU.
VDD from the external board is 1.8 V or 3.3 V, thanks to the on board voltage converter.
SW1 is accessible on bottom side of 32L4R9IDISCOVERY. By default, SW1 is in On
position. To put micro switch in Off position, just push away the switch from ON position as
shown in Table 3.
Table 2. JP10: VDD_STL setting
Jumper Setting Description
JP10
Default setting.
VDD_STL gets power from 32L4R9IDISCOVERY. ST-LINK is
then usable to program the on-board MCU.
VDD_STL gets power from external through CN5. ST-LINK is
then usable to program an external MCU.
Table 3. SW1 switch setting
Switch Setting Description
SW1
Default setting.
SW1 switch is On.
SW1 is Off.
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UM2271 Hardware layout and configuration
77
10.6 Power supply
10.6.1 Power supply sources
32L4R9IDISCOVERY is designed to be powered by +5 V DC power supply. It is possible to
configure the 32L4R9IDISCOVERY to use any of the sources listed in Table 4.
By default, the JP4 header must have a jumper on (1) STLK and SW1 is placed in ON
position. Any JP4 position different from (1) STLK requires SW1 to be placed in OFF
position (see Table 3).
Note: 32L4R9IDISCOVERY must be powered by a power-supply unit or by an auxiliary equipment
complying with the standard EN-60950-1: 2006+A11/2009, and must be safety extra low
voltage (SELV) with limited power capability.
Figure 9 shows a physical description of the 10-pin header JP4 default configuration.
Figure 9. JP4 default configuration
Detailed description of all JP4 possible configurations are listed below and in Table 5:
•STLK: 5 V from the ST-LINK/V2-1 USB connector CN13 with 500 mA current limitation.
Power mechanism of supplying the board by STLINK/V2-1 is explained Section 10.6.3.
Table 4. 32L4R9IDISCOVERY power sources configuration
JP4 configuration
(function)
Power source
connector (pin name) Voltage Available current
(1) STLK (USB_STLINK) CN5 (VBUS) 5 V 500 mA
(3) E5V (ARDUINO) CN16 (VIN) 6 V - 9 V => 5 V Arduino Uno V3 shield
dependent
(5) U5V (USB_OTG_FS) CN8 (VBUS) 5 V 500 mA
(7) ARD (ARDUINO) CN16 (ARD-5V)(1)
1. ARD-5V is a power output pin to Arduino connector CN16 (default) or a power input pin from Arduino
connector CN16, according to JP5 setting. See Table 6 below.
5 V Arduino Uno V3 shield
dependent
(9) CHGR (USB_STLINK) CN5 (VBUS) 5 V Power supply
dependent
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Hardware layout and configuration UM2271
20/78 DocID030906 Rev 2
A jumper must be placed in location STLK of JP4, connecting pins 1 and 2. The green
LED LD8 is lit on to confirm presence of 5 V voltage.
•E5V: 5 V from the 6 V to 9 V DC from VIN pin of Arduino compatible connector CN16
(the U15 regulator is converting VIN into a 5 V voltage). The VIN input voltage is limited
to 9 V to keep temperature of the regulator U15 within its thermal safe area. A jumper
must be placed connecting pins 3 and 4 of JP4. The green LED LD8 is lit on to confirm
presence of 5 V voltage. SW1 must be placed in OFF position.
•U5V: 5 V from the 5 V DC of USB OTG FS user connector CN9. A jumper must be
placed in location USB of JP4, connecting pins 5 and 6.The green LED LD8 is lit on to
confirm presence of 5 V voltage. SW1 must be placed in OFF position.
•ARD: 5 V from the 5 V of Arduino compatible connector CN16. A jumper must be
placed in location ARD of JP4, connecting pins 7 and 8. The green LED LD8 is lit on to
confirm presence of 5 V voltage and at t the same time, pins 2 and 3 of JP5 must be
connected to get 5 V power from Arduino. SW1 must be placed in OFF position. In
case the main board provides 5 V to Arduino compatible connector CN16, which is the
default configuration, pins 1 and 2 of JP5 must be connected (see Table 6).
•CHGR: 5 V from 5 V DC power charger connected to USB STLINK (CN13). In this
case, if 32L4R9IDISCOVERY is powered by an external USB charger, then the debug
on CN13 is not available. When CHGR input is chosen, it is not recommended to
connect a PC on USB STLINK, because the 500 mA limitation is no more effective and
this may damage the PC. A jumper must be placed in location CHGR of JP4,
connecting pins 9 and 10. The green LED LD8 is lit on to confirm presence of 5 V
voltage. SW1 must be placed in OFF position.
Table 5. JP4: power source selector setting
Jumper Setting Description
JP4
Default setting.
32L4R9IDISCOVERY is supplied though CN13 Micro-B
ST-LINK/V2-1 connector.
32L4R9IDISCOVERY is supplied though Arduino connector
CN16 (VIN).
32L4R9IDISCOVERY is supplied though USB OTG FS
connector CN9.
32L4R9IDISCOVERY powers ARDUINO or is supplied by
ARDUINO, according to JP5 setting in Table 6 below.
32L4R9IDISCOVERY is supplied though CN13 Micro-B ST-
LINK/V2-1 connector. In that case, the SB36 solder bridge must
be soldered.
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