## Converting SAMD21J18 to SAMD21E18 Usb Host MSD Project

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I am suffering from issues going from my SAMD21J18 that has been working 100% with usb for months to a new SAMD21E18. Looking at the datasheet everything looks identical except the pincount. That is it has pretty much all the same internal hardware minus a couple things like SERCOM4/5 etc.

After copying the circuit from one to the other and having an identical layout, the USB responds with 480 Counts of SOF that distributes these internal messages from the stack:

CONN
CTRL Error
CTRL Error
CTRL Error
CTRL Error
SUSP

That is, I plug in my USB stick at the top, 120 SOF callbacks occur between each of the CTRL Error's. Then the communication gets suspended. When I initially plug in my USB I can see an increase in current draw on my PCB from 30mA to 55mA for the duration of the communication. Once the "SUSP" message occurs, the current drops back to 30mA, as if my 4GB USB 2.0 stick was never plugged in. Remove the stick, place it back in and all the above occurs once more.

I have tried 3 separate applications so far:

- The samd21j18 project, simply changing the definitions in the symbols and the device in the compiler. Everything in the app including uart works fine, USB didn't

- Created a sample project based on the samd21j18 xpro and made the same mods as above, same issues

- Created a new project and followed the USB MSC bootloader app note religiously, same issue.

All the above resulted in identical issues. This would leave me to believe that it is either because of a difference between the two chips, or more likely, a hardware issue which I simply cannot see :(

Scoping the hardware I can see:

- 32.768khz crystal is operating

- the SOF occurs on both the DM and DP lines

- My power supply at the usb sits steady at 4.99V.

- Doing a load test on the USB port with 170mA the voltage doesn't go below 4.97V, even when I "suddenly" plug it in

- I tried with all 3 of the custom board i made, all give the same results

- I tried with 4 different usb sticks, each works with my SAMD21J18 and is formatted for FAT32

- After the current drops off after errors, DP remains high, DM remains low

Removing the tvs from the schematic and simply shorting those pins, resulted in no changes.

0.5 Ohms tested across the CMC from SAMD21E18 DP/DM pins directly to USB connector. No surrounding shorts that I can see. Vcc and Gnd both O/C against DP and DM

The only odd thing I could see was that my DP line while it has a steady state high, it sometimes during this process just 'drops' to 0V for a few ms

Attached is my schematic.

Any thoughts would be awesome!

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Last Edited: Wed. Nov 28, 2018 - 05:12 AM
This reply has been marked as the solution.

I got a usb cdc echo example working. This leads me to believe there is something wrong with their driver.

I started playing around with my samd21 xpro with all the examples I could find in both atmel start and default atmel examples. In both situations I couldn't get the xpro board to work sadly, only with cdc did things work straight away :(

Looks like I might be spending a bit of a time to work through and fix atmel bugs with usb host...woop.

----------EDIT-------

Looking at my SOF I noticed that it was running at ~170Hz (1K/6) as seen in the above scope image. The SOF should be ran at 1KHz. So it had to do with my clock, or at least something in it! Using the working Atmel Start CDC app as a base, I scraped through all the active clocks when debugging in my SYSCTRL. After manually changing a couple of them, everything started working. To be honest I am not sure what did it... But this is the result.

/**
* \file
*
* \brief SAM D21 Clock configuration
*
*
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
*    this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
*    this list of conditions and the following disclaimer in the documentation
*    and/or other materials provided with the distribution.
*
* 3. The name of Atmel may not be used to endorse or promote products derived
*    from this software without specific prior written permission.
*
* 4. This software may only be redistributed and used in connection with an
*    Atmel microcontroller product.
*
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*
*/
/*
* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
*/
#include <clock.h>

#ifndef CONF_CLOCKS_H_INCLUDED
#  define CONF_CLOCKS_H_INCLUDED

/* System clock bus configuration */
#  define CONF_CLOCK_CPU_CLOCK_FAILURE_DETECT     false
#  define CONF_CLOCK_FLASH_WAIT_STATES            1
#  define CONF_CLOCK_CPU_DIVIDER                  SYSTEM_MAIN_CLOCK_DIV_1
#  define CONF_CLOCK_APBA_DIVIDER                 SYSTEM_MAIN_CLOCK_DIV_1
#  define CONF_CLOCK_APBB_DIVIDER                 SYSTEM_MAIN_CLOCK_DIV_1
#  define CONF_CLOCK_APBC_DIVIDER                 SYSTEM_MAIN_CLOCK_DIV_1

/* SYSTEM_CLOCK_SOURCE_OSC8M configuration - Internal 8MHz oscillator */
#  define CONF_CLOCK_OSC8M_PRESCALER              SYSTEM_OSC8M_DIV_1
#  define CONF_CLOCK_OSC8M_ON_DEMAND              true
#  define CONF_CLOCK_OSC8M_RUN_IN_STANDBY         false

/* SYSTEM_CLOCK_SOURCE_XOSC configuration - External clock/oscillator */
#  define CONF_CLOCK_XOSC_ENABLE                  false
#  define CONF_CLOCK_XOSC_EXTERNAL_CRYSTAL        SYSTEM_CLOCK_EXTERNAL_CRYSTAL
#  define CONF_CLOCK_XOSC_EXTERNAL_FREQUENCY      12000000UL
#  define CONF_CLOCK_XOSC_STARTUP_TIME            SYSTEM_XOSC_STARTUP_32768
#  define CONF_CLOCK_XOSC_AUTO_GAIN_CONTROL       true
#  define CONF_CLOCK_XOSC_ON_DEMAND               true
#  define CONF_CLOCK_XOSC_RUN_IN_STANDBY          false

/* SYSTEM_CLOCK_SOURCE_XOSC32K configuration - External 32KHz crystal/clock oscillator */
#  define CONF_CLOCK_XOSC32K_ENABLE               true
#  define CONF_CLOCK_XOSC32K_EXTERNAL_CRYSTAL     SYSTEM_CLOCK_EXTERNAL_CRYSTAL
#  define CONF_CLOCK_XOSC32K_STARTUP_TIME         SYSTEM_XOSC32K_STARTUP_65536
#  define CONF_CLOCK_XOSC32K_AUTO_AMPLITUDE_CONTROL  false
#  define CONF_CLOCK_XOSC32K_ENABLE_1KHZ_OUPUT    false
#  define CONF_CLOCK_XOSC32K_ENABLE_32KHZ_OUTPUT  true
#  define CONF_CLOCK_XOSC32K_ON_DEMAND            false
#  define CONF_CLOCK_XOSC32K_RUN_IN_STANDBY       false

/* SYSTEM_CLOCK_SOURCE_OSC32K configuration - Internal 32KHz oscillator */
#  define CONF_CLOCK_OSC32K_ENABLE                false
#  define CONF_CLOCK_OSC32K_STARTUP_TIME          SYSTEM_OSC32K_STARTUP_130
#  define CONF_CLOCK_OSC32K_ENABLE_1KHZ_OUTPUT    true
#  define CONF_CLOCK_OSC32K_ENABLE_32KHZ_OUTPUT   true
#  define CONF_CLOCK_OSC32K_ON_DEMAND             true
#  define CONF_CLOCK_OSC32K_RUN_IN_STANDBY        false

/* SYSTEM_CLOCK_SOURCE_DFLL configuration - Digital Frequency Locked Loop */
#  define CONF_CLOCK_DFLL_ENABLE                  true
#  define CONF_CLOCK_DFLL_LOOP_MODE               SYSTEM_CLOCK_DFLL_LOOP_MODE_OPEN
#  define CONF_CLOCK_DFLL_ON_DEMAND               false

/* DFLL open loop mode configuration */
#  define CONF_CLOCK_DFLL_FINE_VALUE              (512)

/* DFLL closed loop mode configuration */
#  define CONF_CLOCK_DFLL_SOURCE_GCLK_GENERATOR   GCLK_GENERATOR_1
#  define CONF_CLOCK_DFLL_MULTIPLY_FACTOR         (48000000 / 32768)
#  define CONF_CLOCK_DFLL_QUICK_LOCK              true
#  define CONF_CLOCK_DFLL_TRACK_AFTER_FINE_LOCK   true
#  define CONF_CLOCK_DFLL_KEEP_LOCK_ON_WAKEUP     true
#  define CONF_CLOCK_DFLL_ENABLE_CHILL_CYCLE      true
#  define CONF_CLOCK_DFLL_MAX_COARSE_STEP_SIZE    (0x1f / 4)
#  define CONF_CLOCK_DFLL_MAX_FINE_STEP_SIZE      (0xff / 4)

/* SYSTEM_CLOCK_SOURCE_DPLL configuration - Digital Phase-Locked Loop */
#  define CONF_CLOCK_DPLL_ENABLE                  false
#  define CONF_CLOCK_DPLL_ON_DEMAND               true
#  define CONF_CLOCK_DPLL_RUN_IN_STANDBY          false
#  define CONF_CLOCK_DPLL_LOCK_BYPASS             false
#  define CONF_CLOCK_DPLL_WAKE_UP_FAST            false
#  define CONF_CLOCK_DPLL_LOW_POWER_ENABLE        false

#  define CONF_CLOCK_DPLL_LOCK_TIME               SYSTEM_CLOCK_SOURCE_DPLL_LOCK_TIME_DEFAULT
#  define CONF_CLOCK_DPLL_REFERENCE_CLOCK         SYSTEM_CLOCK_SOURCE_DPLL_REFERENCE_CLOCK_XOSC32K
#  define CONF_CLOCK_DPLL_FILTER                  SYSTEM_CLOCK_SOURCE_DPLL_FILTER_DEFAULT

#  define CONF_CLOCK_DPLL_REFERENCE_FREQUENCY     32768
#  define CONF_CLOCK_DPLL_REFERENCE_DIVIDER       1
#  define CONF_CLOCK_DPLL_OUTPUT_FREQUENCY        48000000

/* DPLL GCLK reference configuration */
#  define CONF_CLOCK_DPLL_REFERENCE_GCLK_GENERATOR  GCLK_GENERATOR_1
/* DPLL GCLK lock timer configuration */
#  define CONF_CLOCK_DPLL_LOCK_GCLK_GENERATOR     GCLK_GENERATOR_1

/* Set this to true to configure the GCLK when running clocks_init. If set to
* false, none of the GCLK generators will be configured in clocks_init(). */
#  define CONF_CLOCK_CONFIGURE_GCLK               true

/* Configure GCLK generator 0 (Main Clock) */
#  define CONF_CLOCK_GCLK_0_ENABLE                true
#  define CONF_CLOCK_GCLK_0_RUN_IN_STANDBY        true
#  define CONF_CLOCK_GCLK_0_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_DFLL
#  define CONF_CLOCK_GCLK_0_PRESCALER             1
#  define CONF_CLOCK_GCLK_0_OUTPUT_ENABLE         false

/* Configure GCLK generator 1 */
#  define CONF_CLOCK_GCLK_1_ENABLE                true
#  define CONF_CLOCK_GCLK_1_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_1_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_XOSC32K
#  define CONF_CLOCK_GCLK_1_PRESCALER             1
#  define CONF_CLOCK_GCLK_1_OUTPUT_ENABLE         true

/* Configure GCLK generator 2 (RTC) */
#  define CONF_CLOCK_GCLK_2_ENABLE                true
#  define CONF_CLOCK_GCLK_2_RUN_IN_STANDBY        true
#  define CONF_CLOCK_GCLK_2_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_OSC8M
#  define CONF_CLOCK_GCLK_2_PRESCALER             1
#  define CONF_CLOCK_GCLK_2_OUTPUT_ENABLE         false

/* Configure GCLK generator 3 */
#  define CONF_CLOCK_GCLK_3_ENABLE                true
#  define CONF_CLOCK_GCLK_3_RUN_IN_STANDBY        true
#  define CONF_CLOCK_GCLK_3_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_DFLL
#  define CONF_CLOCK_GCLK_3_PRESCALER             1
#  define CONF_CLOCK_GCLK_3_OUTPUT_ENABLE         false

/* Configure GCLK generator 4 */
#  define CONF_CLOCK_GCLK_4_ENABLE                false
#  define CONF_CLOCK_GCLK_4_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_4_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_OSC8M
#  define CONF_CLOCK_GCLK_4_PRESCALER             1
#  define CONF_CLOCK_GCLK_4_OUTPUT_ENABLE         false

/* Configure GCLK generator 5 */
#  define CONF_CLOCK_GCLK_5_ENABLE                false
#  define CONF_CLOCK_GCLK_5_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_5_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_OSC8M
#  define CONF_CLOCK_GCLK_5_PRESCALER             1
#  define CONF_CLOCK_GCLK_5_OUTPUT_ENABLE         false

/* Configure GCLK generator 6 */
#  define CONF_CLOCK_GCLK_6_ENABLE                false
#  define CONF_CLOCK_GCLK_6_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_6_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_OSC8M
#  define CONF_CLOCK_GCLK_6_PRESCALER             1
#  define CONF_CLOCK_GCLK_6_OUTPUT_ENABLE         false

//USE FOR WDT ONLY DUE TO EXTRA PRESCALER
/* Configure GCLK generator 7 */
#  define CONF_CLOCK_GCLK_7_ENABLE                true
#  define CONF_CLOCK_GCLK_7_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_7_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_XOSC32K
#  define CONF_CLOCK_GCLK_7_PRESCALER             50	//20s
#  define CONF_CLOCK_GCLK_7_OUTPUT_ENABLE         false

/* Configure GCLK generator 8 */
#  define CONF_CLOCK_GCLK_8_ENABLE                false
#  define CONF_CLOCK_GCLK_8_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_8_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_OSC8M
#  define CONF_CLOCK_GCLK_8_PRESCALER             1
#  define CONF_CLOCK_GCLK_8_OUTPUT_ENABLE         false

#endif /* CONF_CLOCKS_H_INCLUDED */

Last Edited: Wed. Nov 28, 2018 - 05:12 AM