Texas Instruments TMS320C3x - Manual (Page 357)

TMS320C31 Boot Loader
11-2
11.1 TMS320C31 Boot Loader
This section describes how to use the ’C31 microcomputer/boot loader (MCBL/
MP) function. This feature is unique to the ’C31 and ’C32, and is not available
on the ’C30 devices.
11.1.1 TMS320C31 Boot-Loader Description
The boot loader lets you load and execute programs that are received from a
host processor, inexpensive EPROMs, or other standard memory devices. The
programs to be loaded reside in one of three memory-mapped areas identified
as Boot 1, Boot 2, and Boot 3 (see the shaded areas of Figure 4–2 on page 4-6),
or they are received by means of the serial port.
The boot loader supports user-definable byte, half-word, and word-data formats,
as well as 32-bit fixed-burst loads from the ’C31 serial port. See Section 12.2,
Serial Ports, on page 12-15 for a detailed description of the serial-port operation.
The boot-loader code starts at location 0x45 in the on-chip ROM. The source
code is supplied in Appendix B.
11.1.2 TMS320C31 Boot-Loader Mode Selection
The ’C31 boot loader functions as a memory boot loader or a serial-port boot
loader. The boot-loader function is selected by resetting the processor while
driving the MCBL/MP pin high. Use interrupt pins INT3 – INT0 to select the boot-
load operation. Figure 11–1 shows the flow of this operation, which depends on
the mode selected (external memory or serial boot).
- The memory boot loader supports user-definable byte, half-word, and full-
word data formats, allowing the flexibility to load a source program from
memories having widths of 8-, 16-, or 32 bits. The source program must
reside in one of three memory locations as listed in Table 11–1.
Figure 11–2 shows the memory boot-loader flow.
- The serial-port boot loader supports 32-bit fixed-burst transfers, with
externally generated serial-port clock and frame-sync signals. The format
of the incoming data stream is similar to that of the memory boot loader,
except the source memory width and memory configuration word are
omitted. Figure 11–3 shows the serial-port boot-loader flow.