From 5b032243e63e230c504d52ad85d4f275adf1d58d Mon Sep 17 00:00:00 2001 From: Jorge Aparicio Date: Sun, 16 Dec 2018 21:24:10 +0100 Subject: [PATCH] book: add some notes about the timer queue --- book/src/by-example/timer-queue.md | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/book/src/by-example/timer-queue.md b/book/src/by-example/timer-queue.md index a9c3622dec..f8066c2b17 100644 --- a/book/src/by-example/timer-queue.md +++ b/book/src/by-example/timer-queue.md @@ -1,8 +1,16 @@ # Timer queue When the `timer-queue` feature is enabled the RTFM framework includes a *global -timer queue* that applications can use to *schedule* software tasks to run some -time in the future. +timer queue* that applications can use to *schedule* software tasks to run at +some time in the future. + +> **NOTE**: The timer-queue feature can't be enabled when the target is +> `thumbv6m-none-eabi` because there's no timer queue support for ARMv6-M. This +> may change in the future. + +> **NOTE**: When the `timer-queue` feature is enabled you will *not* be able to +> use the `SysTick` exception as a hardware task because the runtime uses it to +> implement the global timer queue. To be able to schedule a software task the name of the task must appear in the `schedule` argument of the context attribute. When scheduling a task the