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doc/README.imx5 1.19 KB
9db1bfa11   David Jander   ARM: MX51: PLL er...
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  U-Boot for Freescale i.MX5x
  
  This file contains information for the port of U-Boot to the Freescale
  i.MX5x SoCs.
  
  1. CONFIGURATION OPTIONS/SETTINGS
  ---------------------------------
  
  1.1 CONFIG_MX51_PLL_ERRATA: Workaround for i.MX51 PLL errata.
      This option should be enabled by all boards using the i.MX51 silicon
      version up until (including) 3.0 running at 800MHz.
      The PLL's in the i.MX51 processor can go out of lock due to a metastable
      condition in an analog flip-flop when used at high frequencies.
      This workaround implements an undocumented feature in the PLL (dither
      mode), which causes the effect of this failure to be much lower (in terms
      of frequency deviation), avoiding system failure, or at least decreasing
      the likelihood of system failure.
39e857616   Benoît Thébaudeau   mx5: Mark lowleve...
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  1.2 CONFIG_SYS_MAIN_PWR_ON: Trigger MAIN_PWR_ON upon startup.
      This option should be enabled for boards having a SYS_ON_OFF_CTL signal
      connected to GPIO1[23] and triggering the MAIN_PWR_ON signal like in the
      reference designs.
eec3f0242   Benoît Thébaudeau   imx: Document fus...
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  2. CONVENTIONS FOR FUSE ASSIGNMENTS
  -----------------------------------
  
  2.1 MAC Address: It is stored in the words 9 to 14 of fuse bank 1, using the
      natural MAC byte order (i.e. MSB first).