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EFM32 Gecko Starter Kit: Calibrate delay loops, update README

This commit is contained in:
Gregory Nutt 2014-10-29 12:31:55 -06:00
parent cb4cc026a6
commit 5184952c7a
3 changed files with 27 additions and 8 deletions
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31
configs/efm32-g8xx-stk/README.txt
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@ -29,13 +29,32 @@ STATUS
======
2014-10-28. Testing is still in progress. At this point all basic boot
operations are successful: The LEDs work and the application tasks appear
to be successfully started. LED2 is on and LED0 is glowing (meaning that
interrupts are being processed). However, I get no output on PE0. Data
appears to be sent (at least by efm32_lowputc()). However, no signal
activity is present on PE0.
operations are successful: The LEDs work and the application tasks appear
to be successfully started. LED2 is on and LED0 is glowing (meaning that
interrupts are being processed). However, I get no output on PE0. Data
appears to be sent (at least by efm32_lowputc()). However, no signal
activity is present on PE0.
I am, of course, thinking that this is a pin configuration issue.
2014-10-29: The NuttX is running on the EFM32 Gecko Starter Kit. There
are not many peripherals to test in that configuration, but the NuttShell
(NSH) is working over LEUART0 at 2400 baud (certainly that could go up
to 4800. The documentation says that 9600 is also possible on the
LEUART, but I am not sure how).
I originally planned to use UART0 at 115200 baud, but I never could get
any output from the board. I reviewd my pin configuration and clocking
carefully and the USART seems to think it is working correctly. So I
am thinking that there is some board issue that prohibits that option
(probably because UART0 is used with the board controller???). Pins
are not available for other U[S]ARTs on the board.
2014-10-29: Calibrated the delays loops.
2014-10-29: The start-up time is long -- about a second. I have traced
this to the default delay in bringing up the LFCLK in efm32_clockconfig.
The default, reset setting of the LFXOTIMEOUT field of the CMU_CTRL
register is 3 which corresponds to a delay of 32768 cycles, or a full
second. I have not experimented to see if this delay can be reduced.
LEDs
====

2
configs/efm32-g8xx-stk/nsh/defconfig
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@ -192,7 +192,7 @@ CONFIG_ARCH_HAVE_RAMVECTORS=y
#
# Board Settings
#
CONFIG_BOARD_LOOPSPERMSEC=4531
CONFIG_BOARD_LOOPSPERMSEC=2662
# CONFIG_ARCH_CALIBRATION is not set
#

2
configs/olimex-efm32g880f128-stk/nsh/defconfig
View File

@ -189,7 +189,7 @@ CONFIG_ARCH_HAVE_RAMVECTORS=y
#
# Board Settings
#
CONFIG_BOARD_LOOPSPERMSEC=4531
CONFIG_BOARD_LOOPSPERMSEC=2662
# CONFIG_ARCH_CALIBRATION is not set
#