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authorTomas Vanek <vanekt@fbl.cz>2015-05-15 11:14:11 +0200
committerSpencer Oliver <spen@spen-soft.co.uk>2015-11-20 18:26:05 +0000
commit751e2454bf076708d3e695833c4def460ab41d8b (patch)
treeb295038edf1a40008c4a45f520956a6793a61852 /doc
parent64802b79391c71474fd7f0a1d9d6c654fb959300 (diff)
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at91samd: handle reset run/halt in DSU
Atmel introduced a "Device Service Unit" (DSU) that holds the CPU in reset if TCK is low when srst (RESET_N) is deasserted. Function is similar to SMAP in ATSAM4L, see http://openocd.zylin.com/2604 Atmel's EDBG adapter handles DSU reset correctly without this change. An ordinary SWD adapter leaves TCK in its default state, low. So without this change any use of sysresetreq or srst locks the chip in reset state until power is cycled. A new function dsu_reset_deassert is called as reset-deassert-post event handler. It optionally prepares reset vector catch and DSU reset is released then. Additionally SWD clock comment is fixed in at91samdXX.cfg and clock is lowered a bit to ensure a margin for RC oscillator frequency deviation. adapter_nsrst_delay 100 is commented out because is no more necessary after http://openocd.zylin.com/2601 Change-Id: I42e99b1b245f766616c0a0d939f60612c29bd16c Signed-off-by: Tomas Vanek <vanekt@fbl.cz> Reviewed-on: http://openocd.zylin.com/2778 Tested-by: jenkins Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
Diffstat (limited to 'doc')
-rw-r--r--doc/openocd.texi9
1 files changed, 9 insertions, 0 deletions
diff --git a/doc/openocd.texi b/doc/openocd.texi
index 7ae2a3f..14835a9 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -4933,6 +4933,9 @@ flash bank $_FLASHNAME aduc702x 0 0 0 0 $_TARGETNAME
@anchor{at91samd}
@deffn {Flash Driver} at91samd
@cindex at91samd
+All members of the ATSAMD, ATSAMR, ATSAML and ATSAMC microcontroller
+families from Atmel include internal flash and use ARM's Cortex-M0+ core.
+This driver uses the same cmd names/syntax as @xref{at91sam3}.
@deffn Command {at91samd chip-erase}
Issues a complete Flash erase via the Device Service Unit (DSU). This can be
@@ -4980,6 +4983,12 @@ at91samd bootloader 16384
@end example
@end deffn
+@deffn Command {at91samd dsu_reset_deassert}
+This command releases internal reset held by DSU
+and prepares reset vector catch in case of reset halt.
+Command is used internally in event event reset-deassert-post.
+@end deffn
+
@end deffn
@anchor{at91sam3}