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UM10375
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© NXP B.V. 2011. All rights reserved.
User manual
Rev. 3 — 14 June 2011
59 of 368
NXP Semiconductors
UM10375
Chapter 5: LPC13xx Power profiles
The above code specifies a 12 MHz PLL input clock, a system clock of approximately
16.5 MHz and no locking time-out.
set_pll
returns PLL_CMD_SUCCESS in
result[0]
and
16000 in
result[1]
. The new system clock is 16 MHz.
5.6 Power routine
5.6.1 set_power
This routine configures the device’s internal power control settings according to the calling
arguments. The goal is to reduce active power consumption while maintaining the feature
of interest to the application close to its optimum.
Remark:
The set_power routine was designed for systems employing the configuration of
SYSAHBCLKDIV = 1 (System clock divider register, see
). Using
this routine in an application with the system clock divider not equal to 1 might not improve
microcontroller’s performance as much as in setups when the main clock and the system
clock are running at the same rate.
set_power
returns a result code that reports whether the power setting was successfully
changed or not.
Fig 8.
Power profiles usage
using power profiles and
changing system clock
current_clock,
new_clock , new_mode
use power routine call
to change mode to
DEFAULT
use either clocking routine call or
custom code to change system clock
from current_clock to new_clock
use power routine call
to change mode to
new_mode
end