cpu/sam0_common: uart: document frequency constraints

RIOT-OS · Jul 28, 2020 · 003c25b · 003c25b
1 parent e1f84de
commit 003c25b
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/cpu/sam0_common/include/periph_cpu_common.h b/cpu/sam0_common/include/periph_cpu_common.h
@@ -210,6 +210,16 @@ typedef enum {
 
 /**
  * @brief   UART device configuration
+ *
+ *          The frequency f() of the clock `gclk_src` must fulfill the condition
+ *
+ *              16 * baud < f(gclk_src) ≤ 2²⁰ * baud
+ *
+ *          in Asynchronous Arithmetic mode and
+ *
+ *              16 * baud < f(gclk_src) ≤ 2¹⁷ * baud
+ *
+ *          in Asynchronous Fractional mode
  */
 typedef struct {
     SercomUsart *dev;       /**< pointer to the used UART device */