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Gregory Nutt 2015-05-25 10:23:11 -06:00
parent 63ece47790
commit 9c939cd519
1 changed files with 27 additions and 44 deletions
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configs/saml21-xplained/README.txt
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@ -8,6 +8,7 @@ ATSAML21J18A MCU.
Contents
========
- STATUS/ISSUES
- Modules
- Development Environment
- GNU Toolchain Options
@ -20,6 +21,24 @@ Contents
- SAML21 Xplained Pro-specific Configuration Options
- Configurations
STATUS/ISSUES
=============
- Since this port is a leverage of the SAMD20 Xplained port, some of the
STATUS/ISSUES in the SAMD20 Xplained README.txt may apply here as well.
- 2015-5-25: The basic port is running but using OSC16M and with a CPU
frequency of only 16MHz. Attempts to use the DFLL to get the 48MHz
has so far been unsuccessful. I can't find any example in the Atmel
ASF files the run at 48MHz with the DFLL (in closed loop mode) or
with the DPLL.
If I enable the DFLL now in open loop mode. It kind of works but with
a some random CPU frequenycy (soemthing like 13.7MHz). Of course the
results in a crazy UART baud so that is not usable. If I try to enable
the DFLL in closed loop mode, it hangs waiting for the DFLL to become
ready. I have not tried the DPLL.
Modules
=======
@ -753,7 +772,10 @@ Configuration sub-directories
an 'unsigned long int'. If this error occurs, then you may need to
toggle the value of CONFIG_CXX_NEWLONG.
4. If the I/O1 module is connected to the SAML21 Xplained Pro, then
4. WARNING: This info comes from the SAMD20 Xplained README. I have
not tried the I/O1 module on the SAML21!
If the I/O1 module is connected to the SAML21 Xplained Pro, then
support for the SD card slot can be enabled by making the following
changes to the configuration. These changes assume that the I/O1
modules is connected in EXT1. Most of the modifications necessary
@ -824,6 +846,9 @@ Configuration sub-directories
This is a test
nsh>
5. WARNING: This info comes from the SAMD20 Xplained README. I have
not tried the OLED1 module on the SAML21!
5. If the OLED1 module is connected to the SAML21 Xplained Pro, then
support for the OLED display can be enabled by making the following
changes to the configuration. These changes assume that the I/O1
@ -890,49 +915,7 @@ Configuration sub-directories
CONFIG_EXAMPLES_NXHELLO_BPP=1 : One bit per pixel
CONFIG_EXAMPLES_NXHELLO_EXTERNINIT=y : Special initialization is required.
* The OLED is monochrome so the only "colors" are blacka nd white.
* The OLED is monochrome so the only "colors" are black and white.
The default "colors" will give you while text on a black background.
You can override the faults it you want black text on a while background.
NOTE: One issue that I have seen with the NXHello example when
running as an NSH command is that it only works the first time.
So, after you run the 'nxhello' command one time, you will have to
reset the board before you run it again.
This is clearly some issue with initializing, un-initializing, and
then re-initializing. If you want to fix this, patches are quite
welcome.
STATUS/ISSUES:
1. The FLASH waitstates is set to 2 (see include/board.h). According to
the data sheet, it should work at 1 but I sometimes see crashes when
the waitstates are set to one (about half of the time) (2014-2-18).
2. Garbage appears on the display sometimes after a reset (maybe 20% of
the time) or after a power cycle (less after a power cycle). I don't
understand the cause of of this but most of this can be eliminated by
simply holding the the reset button longer and releasing it cleanly
(then it fails maybe 5-10% of the time, maybe because of button
chatter?) (2014-2-18).
- The garbage is not random: It is always the same.
- This is not effected by BAUD rate. Curiously, the same garbage
appears at different BAUD settings implying that this may not even
be clock related???
- The program seems to be running normally, just producing bad output.
3. SPI current hangs so not much progress has been made testing the I/O1
module. The hang occurs because the SPI is waiting for SYNCBUSY to
be cleared after enabling the SPI. This even does not happen and so
causes the hang.
Another note: Enabling the SPI on SERCOM0 also seems to interfere
with the USART output on SERCOM4. Both symptoms imply some clock-
related issue.
The configuration suggests CONFIG_MMCSD_HAVECARDDETECT=y, but as of
this writing, there is no support for EIC pin interrupts.
4. OLED1 module is untested. These instructions were just lifted from
the SAM4L Xplained Pro README.txt file.