From c7f6e924dccf577c870b81ae24ae69785acd5bcb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Robert=20J=C3=B6rdens?= Date: Thu, 3 Feb 2022 12:58:50 +0100 Subject: [PATCH] Update tips_monotonic_impl.md * There is no RTIC 0.6, only several RCs. * Timers without interrupts (like the DWT cycle counter alone) will not be useful for `Monotonic` impls. * Clarified some of the descriptions of the various implementations. --- book/en/src/by-example/tips_monotonic_impl.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/book/en/src/by-example/tips_monotonic_impl.md b/book/en/src/by-example/tips_monotonic_impl.md index 38f3e92d8b..3b50c34aef 100644 --- a/book/en/src/by-example/tips_monotonic_impl.md +++ b/book/en/src/by-example/tips_monotonic_impl.md @@ -9,10 +9,10 @@ Implementing time counting that supports large time spans is generally **difficu implementing time handling was a common problem. Moreover, the relation between time and timers used for scheduling was difficult to understand. -For RTIC 0.6 we instead assume the user has a time library, e.g. [`fugit`] or [`embedded_time`], +For RTIC 1.0 we instead assume the user has a time library, e.g. [`fugit`] or [`embedded_time`], as the basis for all time-based operations when implementing `Monotonic`. -This makes it almost trivial to implement the `Monotonic` trait allowing the use of any timer in -the system for scheduling. +This makes it much easier to correctly implement the `Monotonic` trait allowing the use of +almost any timer in the system for scheduling. The trait documents the requirements for each method, and for inspiration here is a list of `Monotonic` implementations: @@ -20,8 +20,8 @@ and for inspiration here is a list of `Monotonic` implementations: - [`STM32F411 series`], implemented for the 32-bit timers - [`Nordic nRF52 series Timer`], implemented for the 32-bit timers - [`Nordic nRF52 series RTC`], implemented for the RTCs -- [`Systick based`], runs at a fixed rate - some overhead but simple -- [`DWT and Systick based`], a more efficient `Systick` based implementation, but requires `DWT` +- [`Systick based`], runs at a fixed interrupt (tick) rate - with some overhead but simple and with support for large time spans +- [`DWT and Systick based`], a more efficient (tickless) implementation - requires both `SysTick` and `DWT`, supports both high resolution and large time spans If you know of more implementations feel free to add them to this list.