Sir,
I am working on Cortex-M4 over serial wire debug protocol, i am able to read IDCODE(0x2ba01477) which is correct as per arm cortex m4 technical reference manual, and i am writing 0x50000000 to CTRLSTAT register to enable CSYSPWRUPREQ and CDBGPWRREQ which is also success without any ACK error,but the thing is when i am trying to read the CTRLSTAT register i got 0xffffffff . I don't understand what might be the problem,Please suggest me what would be the problem??
Thanks & Regards
Excellent news. Thank you for letting us know and also that you kept going when it wasn't easy.
I am very convinced that this will be valuable help for anyone who implements the SWD protocol in their own applications.
hi sir,
may i know where could i found detailed explanation about watch points and break points ?? in reference manual he given a little bit but i need in programmer view where could i get such information??
Thanks & Regards.
Unfortunately I'm not an expert in this area, so I don't know much about breakpoints and watchpoints.
I went to the ARM Information Center and searched for 'watchpoint', as this is not technology specific to the STM device, but it's ARM technology.
Scrolling down, I find the results for ARM Cortex-M4 Processor Technical Reference Manual, I click it, and I click the DWT Programmers Model link in there.
This shows addresses of hardware registers.
If you look at CWT_CTRL, it says "See [a]", which refers to a note giving you some more information: There are (up to) four comparators for watchpoints and triggers.
In RM0090, sectino 38.13, you'll find some information about what's implemented in your device, combining this with the information found in the Cortex-M4 Technical Reference Manual should get you a bit further.
Please try ARMv7-M Architecture Reference Manual. You need to register on ARM web site to download this document.
(ARMv7-M Architecture Reference Manual)
Section C 1.8 for DWT (watchpoint), C 1.11 for FPB (breakpoint) and C 1.6 for debug registers in the processor for halting control.
regards,
Joseph