Z-World Wolf BL2600, Руководство пользователя

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30 Wolf (BL2600)
3.8 Other Hardware
3.8.1 Clock Doubler
The BL2600 takes advantage of the Rabbit 3000 microprocessor’s internal clock doubler.
A built-in clock doubler allows half-frequency crystals to be used to reduce radiated emis-
sions. The 44.2 MHz frequency specified for the BL2600 is generated using a 22.12 MHz
resonator.
The clock doubler may be disabled if 44.2 MHz clock speeds are not required. Disabling
the Rabbit 3000 microprocessor’s internal clock doubler will reduce power consumption
and further reduce radiated emissions. The clock doubler is disabled with a simple change
to the BIOS as described below.
3.8.2 Spectrum Spreader
The Rabbit 3000 features a spectrum spreader, which helps to mitigate EMI problems. By
default, the spectrum spreader is on automatically, but it may also be turned off or set to a
stronger setting. The means for doing so is through a simple change to the following BIOS
line in a way that is similar to the clock doubler described above.
#define ENABLE_SPREADER 1 // Set to 0 to disable spectrum spreader.
#define SPREADER_SETTING 0 // 0 = normal spreading, 1 = strong spreading
NOTE: The strong spectrum-spreading setting is not recommended since it may limit the
maximum clock speed or the maximum baud rate.
1. Open the BIOS source code file,
RABBITBIOS.C
in the
BIOS
directory.
2. Change the line
#define CLOCK_DOUBLED 1 // set to 1 to double clock if
// Rabbit 2000: crystal <= 12.9024 MHz,
// Rabbit 3000: crystal <= 26.7264 MHz,
// or to 0 to always disable clock doubler
to read as follows.
#define CLOCK_DOUBLED 0
3. Save the change using
File > Save
.