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-rw-r--r--Bootloaders/CDC/BootloaderCDC.txt24
1 files changed, 21 insertions, 3 deletions
diff --git a/Bootloaders/CDC/BootloaderCDC.txt b/Bootloaders/CDC/BootloaderCDC.txt
index 55e5e55a4..5f24a16e5 100644
--- a/Bootloaders/CDC/BootloaderCDC.txt
+++ b/Bootloaders/CDC/BootloaderCDC.txt
@@ -59,9 +59,27 @@
*
* \section Sec_Running Running the Bootloader
*
- * This bootloader is designed to be started via the HWB mechanism of the USB AVRs; ground the HWB pin (see device
- * datasheet) then momentarily ground /RESET to start the bootloader. This assumes the HWBE fuse is set and the BOOTRST
- * fuse is cleared.
+ * On the USB AVR8 devices, setting the \c HWBE device fuse will cause the bootloader to run if the \c HWB pin of
+ * the AVR is grounded when the device is reset.
+ *
+ * The are two behaviours of this bootloader, depending on the device's fuses:
+ *
+ * <b>If the device's BOOTRST fuse is set</b>, the bootloader will run any time the system is not reset from
+ * the external reset pin, unless no valid user application has been loaded. To initiate the bootloader, the
+ * device's external reset pin should be grounded.
+ *
+ * <b>If the device's BOOTRST fuse is not set</b>, the bootloader will run only if initiated via a software
+ * jump, or if the \c HWB pin was low during the last device reset (if the \c HWBE fuse is set).
+ *
+ * For board specific exceptions to the above, see below.
+ *
+ * \subsection SSec_XPLAIN Atmel Xplain Board
+ * Ground the USB AVR JTAG's \c TCK pin to ground when powering on the board to start the bootloader. This assumes the
+ * \c HWBE fuse is cleared and the \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
+ *
+ * \subsection SSec_Leonardo Arduino Leonardo Board
+ * Ground \c IO13 when powering the board to start the bootloader. This assumes the \c HWBE fuse is cleared and the
+ * \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
*
* For board specific exceptions to the above, see below.
*