ARM ARM DUI 0224I - page 205

Programmer’s Reference
ARM DUI 0224I Copyright © 2003-2010 ARM Limited. All rights reserved. 4-39
4.3.19 Oscillator reset registers, SYS_OSCRESETx
The oscillator reset registers, SYS_OSCRESET0 to SYS_OSCRESET4, at
0x1000008C – 0x1000009C are read/write registers that control the frequency of the clocks
generated by clock generators OSC0, OSC1, OSC2, OSC3, and OSC4 if the DEV CHIP
RECONFIG pushbutton is pressed.
Figure 4-19 shows the bit assignment of the registers.
Figure 4-19 Oscillator Register, SYS_OSCRESETx
Note
Before writing to a SYS_OSCRESETx register, unlock it by writing the value
0x0000A05F to the SYS_LOCK register (see Lock Register, SYS_LOCK on page4-24).
After writing the SYS_OSCRESETx register, relock it by writing any value other than
0x0000A05F to the SYS_LOCK register.
For more detail on bit values, see ICS307 programmable clock generators on page3-48
and Oscillator registers, SYS_OSCx on page 4-23.
Note
At power-on reset (nSYSPOR), the SYS_OSCRESETx are loaded with the same
default values used for SYS_OSCx.
The values of the SYS_OSCRESETx values can be changed after powering on. Pushing
the DEV CHIP RECONFIG pushbutton loads the values of the SYS_OSCRESETx
registers into the SYS_OSCx registers and loads the programmable oscillators with the
new values.