README.imx31 1.1 KB

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  1. U-Boot for Freescale i.MX31
  2. This file contains information for the port of U-Boot to the Freescale
  3. i.MX31 SoC.
  4. 1. CONFIGURATION OPTIONS/SETTINGS
  5. ---------------------------------
  6. 1.1 Configuration of MC13783 SPI bus
  7. ------------------------------------
  8. The power management companion chip MC13783 is connected to the
  9. i.MX31 via an SPI bus. Use the following configuration options
  10. to setup the bus and chip select used for a particular board.
  11. CONFIG_MC13783_SPI_BUS -- defines the SPI bus the MC13783 is connected to.
  12. Note that 0 is CSPI1, 1 is CSPI2 and 2 is CSPI3.
  13. CONFIG_MC13783_SPI_CS -- define the chip select the MC13783 s connected to.
  14. 1.2 Timer precision
  15. -------------------
  16. CONFIG_MX31_TIMER_HIGH_PRECISION
  17. Enable higher precision timer. The low-precision timer
  18. (default) provides approximately 4% error, whereas the
  19. high-precision timer is about 0.4% accurate. The extra
  20. accuracy is achieved at the cost of higher computational
  21. overhead, which, in places where time is measured, should
  22. not be critical, so, it should be safe to enable this
  23. option.