diff options
| author | NIIBE Yutaka <gniibe@fsij.org> | 2013-11-03 12:10:22 +0900 |
|---|---|---|
| committer | NIIBE Yutaka <gniibe@fsij.org> | 2013-11-03 12:10:22 +0900 |
| commit | e957d1aff84b2d7020dd6ad453363da4ffdd5983 (patch) | |
| tree | 4456f622e03bbcde0ddfdf817a7ffa7415a9d942 /NEWS | |
| parent | 05e6bda381922dd0890615abdc55fc809e12c9de (diff) | |
Version 0.01release/0.01
Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 43 |
1 files changed, 43 insertions, 0 deletions
@@ -0,0 +1,43 @@ +NEWS - Noteworthy changes + +* Major changes in Chopstx 0.01 + + Released 2013-11-03, by NIIBE Yutaka + +** Interrupt handling change +There was a bug in 0.00, which caused spurious interrupts. Every +interrupt event caused two events. Specifically, after valid +interrupt event (for the caller of chopstx_intr_wait), another +spurious event was always occurred. This was fixed. + +In the design of Chopstx, interrupt handling is done by a thread. +Lower level interrupt handler just accepts interrupt, disabling the +interrupt, and switchs the control to the thread. It is the thread to +check the cause of interrupt, to process it, and to clear the cause. +Next call to chopstx_intr_wait will enable the interrupt again. + +The bug was related to pending interrupt flag. Pending interrupt flag +for a specific interrupt is set, on return from handler mode if the +cause is still active. With traditional interrupt handling, lower +level interrupt handler processes it and clears the cause. Thus, +pending interrupt flag is not set on return. + +In Chopstx, pending interrupt flag was always set, because the control +goes from lower level interrupt handler (in handler mode) to a +interrupt handling thread which processes the interrupt. In 0.01, new +internal routine chx_clr_intr is introduced, and pending interrupt +flag is cleared within chopstx_intr_wait after waked up. + +For detail of interrupt operation, see the section B.3.4, Nested +Vectored Interrupt Controller (NVIC), in the ARM v7-M Architecture +Reference Manual. The subsection, B3.4.1, Theory of operation, +explains how it works. + + +** gpio_init change +Now, gpi_init support AFIO mapping and another GPIO (GPIO_OTHER) +settings. + +Local Variables: +mode: outline +End: |