Newer
Older
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.