I added a review to fix it: http://openocd.zylin.com/2608
open...@versaloon.com
From: Simon Qian
Date: 2015-03-16 18:39
To: Simon Qian; Tomas Vanek
CC: openocd-devel
Subject: Re: Re: [OpenOCD-devel] vsllink silently ignores changes in
adapter_khz after init
I know the problem, openocd doesn't call jtag->swd.frequency to set SWD
frequency.
But instead, call jtag->speed to set the speed for both JTAG and SWD.
For ftdi:
ftdi_speed will call mpsse_set_frequency to set the speed.
and in ftdi_swd_frequency, will also call mpsse_set_frequency to set the speed.
So ftdi_speed can also apply to SWD.
but for versaloon:
static int vsllink_speed(int speed)
{
if (swd_mode)
return ERROR_OK;
versaloon_interface.adaptors.jtag_raw.config(0, (uint16_t)speed);
return versaloon_interface.adaptors.peripheral_commit();
}
in swd_mode, vsllink_speed will not set the SWD frequency.
To fix it is simple, I can call vsllink_swd_frequency in vsllink_speed in
swd_mode.
Or openocd can call jtag->swd.frequency instead of jtag->speed.
I will send the patch for vsllink_speed if need to fix vsllink.c.
open...@versaloon.com
From: Simon Qian
Date: 2015-03-16 12:06
To: Tomas Vanek
CC: openocd-devel
Subject: Re: [OpenOCD-devel] vsllink silently ignores changes in adapter_khz
after init
I will do a test to modify the swd speed on the run, and capture the SWD
waveform of different speed for a compare.
I think versaloon can change the speed, but the speed parameter may be
calculated wrong.
open...@versaloon.com
From: Tomas Vanek
Date: 2015-03-15 22:58
To: Simon Qian
CC: openocd-devel
Subject: Re: [OpenOCD-devel] vsllink silently ignores changes in adapter_khz
after init
This limit is not imposed in init? Or may I guess - speed is not changed if
lower than limit?
Anyway many thanks for fast action.
Tom
On 15.3.2015 15:25, Simon Qian wrote:
OK, I know the problem, in vsllink code, for SWD speed, the min speed
configurable is 72000.
I will add and test other lower speed.
open...@versaloon.com
From: Tomas Vanek
Date: 2015-03-15 22:16
To: Simon Qian
CC: openocd-devel
Subject: Re: [OpenOCD-devel] vsllink silently ignores changes in adapter_khz
after init
I discovered the problem testing http://openocd.zylin.com/2604 on top of fresh
git master.
at91sam4lXX.cfg includes at91sam4XXX.cfg and it sets adapter_khz 500
Changed version of at91sam4lXX.cfg adjusts to adapter_khz 50 for low initial
clock of "L" version. Works on ftdi, without an effect on vsllink.
Basically you can try any SWD-connected MCU and change adapter_khz manually
after init to minimum and compare speed of mdw before and after
(or better use an oscilloscope)
Tom
On 15.3.2015 14:33, Simon Qian wrote:
I will do a test by connecting telnet, and modify the adapter_khz and do a mdw
command, and will report the result tomorrow.
open...@versaloon.com
From: Simon Qian
Date: 2015-03-15 19:55
To: Tomas Vanek
CC: openocd-devel
Subject: Re: [OpenOCD-devel] vsllink silently ignores changes in adapter_khz
after init
Do you have the script? I will do the same test.
open...@versaloon.com
From: Tomas Vanek
Date: 2015-03-15 19:43
To: Simon Qian
CC: openocd-devel
Subject: Re: vsllink silently ignores changes in adapter_khz after init
Yes, I tested it only on swd. swd keeps the speed set in init.
Tom
On 15.3.2015 12:32, Simon Qian wrote:
Hi,
I remember vsllink can support changing the JTAG speed.
I will do a test and reply soon.
open...@versaloon.com
From: Tomas Vanek
Date: 2015-03-15 18:35
To: Simon Qian
CC: OpenOCD ML
Subject: vsllink silently ignores changes in adapter_khz after init
Hi Simon,
would be possible to implement changing of vsllink speed on the fly?
Some MCUs running at low clock freq after reset need it.
It also breaks some configs where one speed is set in included cfg and
then changed to another.
Thanks
Tom
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