diff --git a/boards/msb-430/Kconfig b/boards/msb-430/Kconfig
index 512e021281..b997d66aae 100644
--- a/boards/msb-430/Kconfig
+++ b/boards/msb-430/Kconfig
@@ -20,4 +20,8 @@ config BOARD_MSB_430
 
     select HAVE_SHT11
 
+config ERROR_MODULES_CONFLICT
+    default "The msb-430 uses the same USART for UART and SPI" if MODULE_PERIPH_SPI && MODULE_PERIPH_UART
+    depends on BOARD_MSB_430
+
 source "$(RIOTBOARD)/common/msb-430/Kconfig"
diff --git a/boards/msb-430/Makefile.features b/boards/msb-430/Makefile.features
index 94c96d14ef..94cf3cc9fe 100644
--- a/boards/msb-430/Makefile.features
+++ b/boards/msb-430/Makefile.features
@@ -4,6 +4,9 @@ FEATURES_PROVIDED += periph_spi
 FEATURES_PROVIDED += periph_timer
 FEATURES_PROVIDED += periph_uart
 
+FEATURES_CONFLICT += periph_spi:periph_uart
+FEATURES_CONFLICT_MSG += "Both SPI and UART are provided by the same USART peripheral"
+
 # Various other features (if any)
 
 include $(RIOTBOARD)/common/msb-430/Makefile.features
diff --git a/boards/msb-430/doc.txt b/boards/msb-430/doc.txt
index b49607e099..0e3f610aef 100644
--- a/boards/msb-430/doc.txt
+++ b/boards/msb-430/doc.txt
@@ -18,9 +18,9 @@
 | FPU               | no                                                            |
 | Timers            | 2 (2x 16bit)                                                  |
 | ADCs              | 1x 8 channel 12-bit                                           |
-| UARTs             | 2                                                             |
-| SPIs              | 2                                                             |
-| I2Cs              | 1                                                             |
+| UARTs             | 2 (*)                                                         |
+| SPIs              | 2 (*)                                                         |
+| I2Cs              | 1 (*)                                                         |
 | Vcc               | 1.8 V - 3.6 V (battery holder board provides 3.0 V)           |
 | Datasheet MCU     | [Datasheet](https://www.ti.com/lit/ds/symlink/msp430f1612.pdf)|
 | User Guide MCU    | [User Guide](https://www.ti.com/lit/ug/slau049f/slau049f.pdf) |
@@ -32,6 +32,10 @@
             is used, the supply voltage must initially be at least 2.0 V due to
             the hysteresis of the SVS circuitry. Afterwards the MCU remains
             operational with VCC >= 1.8 V.
+@warning    The MSP430F1612 has two USARTS, which can be configured as UART,
+            SPI, or (only in case of USART0) as I2C bus. Each USART can only
+            provide one serial interface at a time; time sharing is
+            theoretically possible but not yet implemented.
 
 ## Schematics
 
@@ -39,6 +43,37 @@
 
 <img src="https://www.mi.fu-berlin.de/inf/groups/ag-tech/projects/ScatterWeb/pic/blueprints/MSB430_s2.png" alt="Schematics of the MSB-430 (Part 2 / 2)" style="width: 1368px; max-width: 100%;">
 
+### Hardware Limitations
+
+The GPIOs on the MSP430F1612 only have two MUX settings: Being used as digital
+input/output or routed to a peripheral. The MCU has two universal serial
+synchronous/asynchronous communication interfaces (USARTs), which can be
+used to provide either an UART, an SPI, or (only in case of USART0) an I2C bus.
+Every USART signal is available at exactly one GPIO pin.
+
+The UART exposed via the battery holder board (P3.6 and P3.7) can only be
+provided via USART1. In order to support asynchronous reception (e.g. to allow
+interaction via the shell), USART1 needs to be continuously configured as UART
+and cannot be used to provide an SPI bus.
+
+The SPI bus connected to the SD card socket (P5.1, P5.2, and P5.3) can only
+be provided via USART1. Hence, it is not possible to use SPI bus connected to
+the SD card socket while the UART used for `stdio` is in use, as they use the
+same USART. They could be used at the same time, if module `stdin` is not used
+(the UART is output only). However, sharing USARTs is not yet implemented.
+
+The SPI bus of the CC1020 transceiver (used for configuration only) is connected
+to pins P2.0, P2.1, and P2.3. Those pins are not connected to either USART, so
+no hardware SPI can be used to interact with the transceiver. However, the SPI
+is only used for configuration and control of the transceiver, so using a slow
+bit-banging SPI bus won't affect the performance of the transceiver, other than
+for quick power down after transmission or channel hopping. A second two
+wire serial interface (not I2C or compatible) is used to feed data into
+the CC1020 or read data from the CC1020. The serial clock is driven by the
+transceiver and the MCU needs to keep up with providing the frames to send
+bit by bit. Unlike modern transceivers, the CC1020 has no frame buffer and the
+MCU needs to control the transmission and reception on the bit level.
+
 ## Pinout
 
 ### Pinout of the Main MSB 430 Board
diff --git a/boards/msb-430/include/periph_conf.h b/boards/msb-430/include/periph_conf.h
index 12c361a82e..8816508096 100644
--- a/boards/msb-430/include/periph_conf.h
+++ b/boards/msb-430/include/periph_conf.h
@@ -80,8 +80,8 @@ static const msp430_clock_params_t clock_params = {
 #define SPI_NUMOF           (1U)
 
 /* SPI configuration */
-#define SPI_BASE            (&USART_0)
-#define SPI_SFR             (&USART_0_SFR)
+#define SPI_BASE            (&USART_1)
+#define SPI_SFR             (&USART_1_SFR)
 #define SPI_IE_RX_BIT       (1 << 6)
 #define SPI_IE_TX_BIT       (1 << 7)
 #define SPI_ME_BIT          (1 << 6)