Changeset 1eae6f2 in rtems

Timestamp:

10/25/22 09:11:20 (11 months ago)

Author:

Dariusz Sabala <dariusz.sabala@…>

Branches:

master

Children:

89ba2a98

Parents:

f6bcf163

git-author:

Dariusz Sabala <dariusz.sabala@…> (10/25/22 09:11:20)

git-committer:

Sebastian Huber <sebastian.huber@…> (10/26/22 09:47:22)

Message:

bsps/arm: fix Cortex-M7 systick reload value

• see ARM DUI 0646C Arm Cortex-M7 Devices Generic User Guide "The RELOAD value is calculated according to its use. For example, to generate a multi-shot timer with a period of N processor clock cycles, use a RELOAD value of N-1. If the SysTick? interrupt is required every 100 clock pulses, set RELOAD to 99."
• see routines used in CMSIS project for reference

Close #4746.

File:

• bsps/arm/shared/clock/clock-armv7m.c (modified) (1 diff)

bsps/arm/shared/clock/clock-armv7m.c

@@ -91 +91 @@
   interval = (uint32_t) ((freq * us_per_tick) / 1000000);
 
-  systick->rvr = interval;
+  systick->rvr = interval - 1;
   systick->cvr = 0;
   systick->csr = ARMV7M_SYSTICK_CSR_ENABLE | ARMV7M_SYSTICK_CSR_CLKSOURCE;