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Updated README files and comments

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This commit is contained in:
Gregory Nutt 2014-04-07 07:43:28 -06:00
parent 26ea8a3d1d
commit 724ad8d7b5
2 changed files with 59 additions and 16 deletions
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24
configs/sama5d3-xplained/README.txt
View File

@ -2625,6 +2625,30 @@ Configurations
create a very corrupt configuration that may not be easy to recover
from.
4. The SAMA5Dx is running at 396MHz by default in these configurations.
This is because the original timing for the PLLs, NOR FLASH, and SDRAM
came from the Atmel NoOS sample code which runs at that rate.
The SAMA5Dx is capable of running at 528MHz, however, and is easily
re-configured:
Board Selection -> CPU Frequency
CONFIG_SAMA5D3xEK_396MHZ=n # Disable 396MHz operation
CONFIG_SAMA5D3xEK_528MHZ=y # Enable 528MHz operation
If you switch to 528MHz, you should also check the loop calibration
value in your .config file. Of course, it would be best to re-calibrate
the timing loop, but these values should get you in the ballpark:
CONFIG_BOARD_LOOPSPERMSEC=49341 # Calibrated on SAMA5D3-EK at 396MHz
# running from ISRAM
CONFIG_BOARD_LOOPSPERMSEC=65775 # Calibrated on SAMA4D3-Xplained at
# 528MHz running from SDRAM
Operation at 528MHz has been verified but is not the default in these
configurations because most testing was done at 396MHz. NAND has not
been verified at these rates.
Configuration Sub-directories
-----------------------------
Summary: Some of the descriptions below are long and wordy. Here is the

51
configs/sama5d3x-ek/README.txt
View File

@ -2951,6 +2951,35 @@ Configurations
create a very corrupt configuration that may not be easy to recover
from.
4. The SAMA5Dx is running at 396MHz by default in these configurations.
This is because the original timing for the PLLs, NOR FLASH, and SDRAM
came from the Atmel NoOS sample code which runs at that rate.
The SAMA5Dx is capable of running at 528MHz, however, and is easily
re-configured:
Board Selection -> CPU Frequency
CONFIG_SAMA5D3xEK_396MHZ=n # Disable 396MHz operation
CONFIG_SAMA5D3xEK_528MHZ=y # Enable 528MHz operation
If you switch to 528MHz, you should also check the loop calibration
value in your .config file. Of course, it would be best to re-calibrate
the timing loop, but these values should get you in the ballpark:
CONFIG_BOARD_LOOPSPERMSEC=49341 # Calibrated on SAMA5D3-EK at 396MHz
# running from ISRAM
CONFIG_BOARD_LOOPSPERMSEC=65775 # Calibrated on SAMA4D3-Xplained at
# 528MHz running from SDRAM
Operation at 528MHz has been verified but is not the default in these
configurations because most testing was done at 396MHz. NAND has not
been verified at these rates.
5. By default, all of these configurations run from ISRAM or NOR FLASH
(as indicated below in each description of the configuration).
Operation from SDRAM is also an option as described in the paragraph
entitled, "Running NuttX from SDRAM."
Configuration Sub-directories
-----------------------------
Summary: Some of the descriptions below are long and wordy. Here is the
@ -3382,27 +3411,17 @@ Configurations
To-Do List
==========
1) Currently the SAMA5Dx is running at 396MHz in these configurations. This
is because the timing for the PLLs, NOR FLASH, and SDRAM came from the
Atmel NoOS sample code which runs at that rate.
The SAMA5Dx is capable of running at 528MHz, however, and is easily
configured:
Board Selection -> CPU Frequency
CONFIG_SAMA5D3xEK_396MHZ=n
CONFIG_SAMA5D3xEK_528MHZ=y
Basic operation at 528MHz has been verified but is not the default in
these configurations because most testing was done at 396MHz. NAND
has not been verified at these rates.
2) Most of these configurations execute from NOR FLASH. I have been unable
1) Most of these configurations execute from NOR FLASH. I have been unable
to execute these configurations from NOR FLASH by closing the BMS jumper
(J9). As far as I can tell, this jumper does nothing on my board??? I
have been using the norboot configuration to start the program in NOR
FLASH (see just above). See "Creating and Using NORBOOT" above.
UPDATE: It has been confirmed at that there is an issue with the BMS
jumper on my board. However, other NuttX users have confirmed operation
booting directly into NOR FLASH. So although I cannot confirm this
behavior, this appears to be no longer an issue.
3) Neither USB OHCI nor EHCI support Isochronous endpoints. Interrupt
endpoint support in the EHCI driver is untested (but works in similar
EHCI drivers).