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