From 595fbd7346f6a1c393adec737b1587501c47bc4d Mon Sep 17 00:00:00 2001 From: Brandon Matthews Date: Mon, 3 Sep 2018 10:04:13 -0700 Subject: Expand is_debugger_attached note --- src/peripheral/dcb.rs | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/peripheral/dcb.rs b/src/peripheral/dcb.rs index 6189317..3d89c61 100644 --- a/src/peripheral/dcb.rs +++ b/src/peripheral/dcb.rs @@ -34,13 +34,16 @@ impl DCB { // unset bit 24 / TRCENA unsafe { self.demcr.modify(|w| w & !DCB_DEMCR_TRCENA); } - /// Is there a debugger attached? (see note) + /// Is there a debugger attached? (see notes) /// - /// N.B. This function is [reported not to + /// Note 1: This function is [reported not to /// work](http://web.archive.org/web/20180821191012/https://community.nxp.com/thread/424925#comment-782843) /// on Cortex-M0 devices. Per the ARM v6-M Architecture Reference Manual, "Access to the DHCSR /// from software running on the processor is IMPLEMENTATION DEFINED". Indeed, from the /// [Cortex-M0+ r0p1 Technical Reference Manual](http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0484c/BABJHEIG.html), "Note Software cannot access the debug registers." + /// + /// Note 2: This function reads the DHCSR register, and therefore clears S_RESET_ST and + /// S_RETIRE_ST. pub fn is_debugger_attached() -> bool { unsafe { (*Self::ptr()).dhcsr.read() & 0x1 == 1 } } -- cgit v1.2.3