diff --git a/testhal/ADUCM/ADUCM36x/SPI/main.c b/testhal/ADUCM/ADUCM36x/SPI/main.c
index 7ebedc2fe..840426186 100644
--- a/testhal/ADUCM/ADUCM36x/SPI/main.c
+++ b/testhal/ADUCM/ADUCM36x/SPI/main.c
@@ -131,7 +131,8 @@ int main(void) {
     txbuf[i] = (uint8_t)i;
 
   /*
-   * Configuring SPI GPIOs.
+   * Configuring SPI GPIOs. This requires S1 set to 1 in order to have
+   * the SPI PINs connected to the MCU.
    */
   palSetLineMode(LINE_SPI1_CS, PAL_MODE_OUTPUT_PUSHPULL);
   palSetLineMode(LINE_SPI1_MISO, PAL_MODE_MULTIPLEXER(1) |