Spectris Arcom VIPER Quick Start Manual page 14

VIPER RedBoot and AEL Quickstart
CPU Core Clock Frequency and the clock command
Versions of RedBoot on the VIPER up to and including V3I3 initialized the CPU clock to
200MHz at boot time. For version V3I4 this was changed to boot at 400MHz. The
current version (V3I5) no longer changes the clock rate, so it remains at the default
100MHz setting. However, this version introduces an additional command (clock),
which can be used to set the clock to any of the frequencies described in the
frequency scaling
M and N settings which control the clock speed as described in that section. The value
of N should be 10 times the actual value. Therefore, to set N to 1.5, pass the option
–n 15. For example:
•
To set the clock frequency to 300MHz power saving mode:
RedBoot> clock –l 27 –m 1 –n 30
•
To set the clock frequency to 200MHz performance mode:
RedBoot> clock –l 27 –m 2 –n 10
If you have an AEL Development Kit, the default AEL boot script initializes the clock to
400MHz.
© 2005 Arcom Issue D
section on page 22. The clock command takes parameters for the L,
RedBoot
CPU clock
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