From a5ef50c9e7c5042a967cb79e92c8caa3cae9750d Mon Sep 17 00:00:00 2001
From: sciencewhiz <sciencewhiz@users.noreply.github.com>
Date: Mon, 4 Sep 2017 22:03:02 -0700
Subject: [PATCH] Add documentation for PeriodMultiplier (#632)

---
 wpilibc/src/main/native/include/PWM.h              | 14 +++++++++++++-
 .../src/main/java/edu/wpi/first/wpilibj/PWM.java   |  8 ++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/wpilibc/src/main/native/include/PWM.h b/wpilibc/src/main/native/include/PWM.h
index 62260baa9a..2df43b1d83 100644
--- a/wpilibc/src/main/native/include/PWM.h
+++ b/wpilibc/src/main/native/include/PWM.h
@@ -26,7 +26,7 @@ namespace frc {
  * The values supplied as arguments for PWM outputs range from -1.0 to 1.0. They
  * are mapped to the hardware dependent values, in this case 0-2000 for the
  * FPGA. Changes are immediately sent to the FPGA, and the update occurs at the
- * next FPGA cycle. There is no delay.
+ * next FPGA cycle (5.005ms). There is no delay.
  *
  * As of revision 0.1.10 of the FPGA, the FPGA interprets the 0-2000 values as
  * follows:
@@ -41,9 +41,21 @@ class PWM : public SensorBase,
             public ITableListener,
             public LiveWindowSendable {
  public:
+  /**
+   * Represents the amount to multiply the minimum servo-pulse pwm period by.
+   */
   enum PeriodMultiplier {
+    /**
+     * Don't skip pulses. PWM pulses occur every 5.005 ms
+     */
     kPeriodMultiplier_1X = 1,
+    /**
+     * Skip every other pulse. PWM pulses occur every 10.010 ms
+     */
     kPeriodMultiplier_2X = 2,
+    /**
+     * Skip three out of four pulses. PWM pulses occur every 20.020 ms
+     */
     kPeriodMultiplier_4X = 4
   };
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java
index f55a8c467d..3efd077051 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java
@@ -20,7 +20,7 @@ import edu.wpi.first.wpilibj.tables.ITableListener;
  *
  * <p>The values supplied as arguments for PWM outputs range from -1.0 to 1.0. They are mapped to
  * the hardware dependent values, in this case 0-2000 for the FPGA. Changes are immediately sent to
- * the FPGA, and the update occurs at the next FPGA cycle. There is no delay.
+ * the FPGA, and the update occurs at the next FPGA cycle (5.005ms). There is no delay.
  *
  * <p>As of revision 0.1.10 of the FPGA, the FPGA interprets the 0-2000 values as follows: - 2000 =
  * maximum pulse width - 1999 to 1001 = linear scaling from "full forward" to "center" - 1000 =
@@ -33,15 +33,15 @@ public class PWM extends SensorBase implements LiveWindowSendable {
    */
   public enum PeriodMultiplier {
     /**
-     * Period Multiplier: don't skip pulses.
+     * Period Multiplier: don't skip pulses. PWM pulses occur every 5.005 ms
      */
     k1X,
     /**
-     * Period Multiplier: skip every other pulse.
+     * Period Multiplier: skip every other pulse. PWM pulses occur every 10.010 ms
      */
     k2X,
     /**
-     * Period Multiplier: skip three out of four pulses.
+     * Period Multiplier: skip three out of four pulses. PWM pulses occur every 20.020 ms
      */
     k4X
   }