contiki/cpu/cc2538
Benoît Thébaudeau 5261bb861d cc2538: lpm: Fix RTIMER_NOW() upon wake-up
When returning from PM1/2, the sleep timer value (used by RTIMER_NOW()) is not
up-to-date until a positive edge on the 32-kHz clock has been detected after the
system clock restarted. To ensure an updated value is read, wait for a positive
transition on the 32-kHz clock by polling the SYS_CTRL_CLOCK_STA.SYNC_32K bit,
before reading the sleep timer value.

Because of this RTIMER_NOW() fixup, lpm_exit() has to be called at the very
beginning of ISRs waking up the SoC. This also ensures that all clocks and
timers are enabled at the correct frequency and updated before using them
following wake-up.

Without this fix, etimers could sometimes (randomly, depending on timings)
become ultra slow (observed from 10x to 40x slower than normal) if the system
exited PM1/2 very often. This issue occurred more often with PM1.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
2013-12-05 20:23:29 +01:00
..
dev cc2538: lpm: Fix RTIMER_NOW() upon wake-up 2013-12-05 20:23:29 +01:00
usb cc2538: usb: Make the GPIO driving the pull-up optional 2013-11-25 15:15:35 +01:00
cc2538.lds cc2538: Add header file for flash CCA page and use it 2013-12-05 18:45:51 +01:00
clock.c
cpu.c
cpu.h
dbg.c
dbg.h
debug-uart.h
ieee-addr.c
ieee-addr.h
lpm.c cc2538: lpm: Fix RTIMER_NOW() upon wake-up 2013-12-05 20:23:29 +01:00
lpm.h cc2538: lpm: Fix RTIMER_NOW() upon wake-up 2013-12-05 20:23:29 +01:00
Makefile.cc2538 cc2538: Make it possible to use a custom linker script 2013-11-15 15:41:58 +01:00
mtarch.h A massive all-tree automated update of all double inclusion guard #defines that changes from using two underscores as a prefix, which are reserved, to not using two underscores as a prefix 2013-11-24 20:20:11 +01:00
reg.h
rtimer-arch.c cc2538: lpm: Fix RTIMER_NOW() upon wake-up 2013-12-05 20:23:29 +01:00
rtimer-arch.h
slip-arch.c
spi-arch.h cc2538: spi: Add enable and disable functions 2013-11-20 14:20:50 +01:00