MOTOROLA
Bootloader
1-5
1.1.3
Target Consideration
1.1.3.1
56F801
When the TargetDirectives file contains #define DSP56801EVM, this application is built
assuming the existence of an internal relaxation oscillator and corresponding calibration value. At
run-time, the application automatically calibrates the internal relaxation oscillator to run at 8MHz.
Note:
For the 56F801, only processors with a date code GREATER THAN 0152 marked in
the lower right corner of the part contain the internal oscillator calibration value. For
parts built prior to this date, the TargetDirectives file should contain the following for
correct operation:
#define DSP56801EVM
#define PLL_USE_EXTERNAL_OSC
Note:
The 56F802 does NOT have an external oscillator and must therefore have the
following in the TargetDirectives file for correct operation:
#define DSP56801EVM
1.1.3.2
56F827
1.1.3.2.1
56F827 Boot Flash
The 56F827 has 63KB of on-chip Program Flash memory and 1KB of on-chip Program RAM.
Unlike the 56F826, which has dedicated Boot Flash hardware, the 56F827 has no dedicated Boot
Flash hardware. As shown in
Figure 1-3
, Boot Flash is carved from Program Flash 2 and Program
Flash 1. The Bootloader is mapped to Program Flash 2 at location 0xF800 to 0xFFFF.
1.1.3.2.2
56F827 Hardware Reset and COP
The hardware and COP reset vectors are mapped to Program Flash 1 at locations 0x0000 and
0x0002. Unlike the 56F826, which has dedicated Boot Flash hardware, the 56F827 hardware and
COP reset vectors can be erased when programming the first page in Program Flash 1 through the
Bootloader. This can occur if power to the 56F827 is lost when the Bootloader is saving and
erasing the page that contains the reset and COP vectors. If this happens, the Bootloader will not
be available on the next 56F827 reset.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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