RL-ARM: HOW TO SERVICE A WATCHDOG TIMER WHEN USING THE SD FILE SYSTEM

Information in this article applies to:

• RL-ARM RTX Kernel any Version

QUESTION

I am using the RL-ARM SD/MMC flash file system in my application where I also need a watchdog timer. Formatting an SD card or reading/writing big files takes longer than the watchdog overflow period. Which function of the SD/MMC flash file system is called frequently where I can add some code to service the watchdog timer?

ANSWER

The SPI or MMC driver interface module is a good place to service the watchdog timer because these communication functions are called frequently even during a format command. Here are the function and module names for various devices:

• STR91x: 'spi_send()' in module SPI_STR91x.c
• LPC214x: 'spi_send()' in module SPI_LPX214x.c
• LPC23xx: 'mci_command()' in module MCI_LPC23xx.c

MORE INFORMATION

• Refer to spi_send in the RL-ARM User's Guide.

Last Reviewed: Thursday, October 04, 2007