Phytec phyCORE-i.MX 6, Руководство по оборудованию

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System Configuration and Booting
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PHYTEC Messtechnik GmbH 2016 L-808e_2
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6 System Configuration and Booting
Although most features of the i.MX 6 microcontroller are configured and/or programmed
during the initialization routine, other features, which impact program execution, must be
configured prior to initialization via pin termination.
The system start-up configuration includes:
•
Boot mode selection
•
Boot device selection
•
Boot device configuration
The internal ROM code is the first code executed during the initialization process of the
i.MX 6 after POR. The ROM code detects the boot mode by using the boot mode pins
(BOOT_MODE[1:0]), while the boot device is selected and configured by determining the
state of the eFUSEs and/or the corresponding GPIO input pins (BOOT_CFGx[7:0]).
6.1 Boot Mode Selection
The boot mode of the i.MX 6 microcontroller is determined by the configuration of two
boot mode inputs BOOT_MODE[1:0] during the reset cycle of the operational system. These
inputs are brought out at the phyCORE-Connector pins X_BOOT_MODE[1:0] (X1D1, X1C1).
Table 8 shows the possible settings of pins X_BOOT_MODE0 (X1C1) and X_ BOOT_MODE1
(X1D1) and the resulting boot configuration of the i.MX 6.
Table 8: Boot Modes of the phyCORE-i.MX 6
The BOOT_MODE[1:0] lines have 10 kΩ pull-up and pull-down resistors populated on the
module. Hence leaving the two pins unconnected sets the controller to boot mode 2,
internal boot.
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: Default boot mode when pins X_BOOT_MODE[1:0] are left unconnected.
Boot Mode X_ BOOT_MODE1 X_ BOOT_MODE0 Boot Source
0 0 0 Bootconfig from eFUSEs
1 0 1 Serial Downloader
2 1 0 Internal Boot
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3 1 1 reserved