Dsp Bootloader - Texas Instruments OMAP5910 Reference Manual

DSP Subsystem Reset, Clocking, Idle Control, and Boot
12.4

DSP Bootloader

12.4.1 Introduction
12.4.1.1 Bootloader Features
12.4.1.2 DSP Subsystem On-Chip PDROM
228 DSP Subsystem
This section provides a description of the features of the on-chip DSP
bootloader provided with the OMAP5910 and OMAP5912 devices.
OMAP devices contain program code residing in the DSP subsystem PDROM,
called a bootloader. The bootloader is executed by the DSP core when it is
taken out of reset. Depending on the boot mode selected, the DSP core will
branch to an internal or DSP external memory address or go into idle. The
following is a list of the boot modes supported by the bootloader and a
summary of their functional operation:
DSP idle mode. The DSP subsystem is brought out of reset with all of the
-
modules within the DSP module placed in their idle mode.
Direct execution from DSP external memory. The on-chip PDROM is
-
disabled and the interrupt vector table is fetched directly from DSP
external memory.
Branch directly to a starting address. The bootloader directs code
-
execution to an entry point address which is specified by the selected boot
mode. The entry point may be located in either internal or DSP external
memory. Note that the memory at the destination address must be
initialized with valid code before the bootloader is executed. With an
internal memory entry point, the MPU core or system DMA can initialize
the memory through the MPUI port.
The bootloader also offers the following features:
Register controlled boot mode selection. The MPU core can select the
-
boot mode by writing to a bootloader configuration register (described in
section 12.4.2.2).
Multiple entry points. Each boot mode uses a different entry point address.
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The DSP subsystem PDROM contains the bootloader program. The PDROM
may be enabled or disabled based on the settings of the BOOT_MODE bits
in the DSP_BOOT_CONFIG register (section 12.4.2.2). When the PDROM is
disabled, the PDROM memory space is mapped to memory that is external to
the DSP subsystem. Table 102 lists the contents of the DSP PDROM.
SPRU890A