ARM ARM DUI 0224I manual Oscillator reset registers, SYSOSCRESETx

Programmer’s Reference

4.3.19Oscillator reset registers, SYS_OSCRESETx

The oscillator reset registers, SYS_OSCRESET0 to SYS_OSCRESET4, at 0x1000008C–0x1000009Care 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 page 4-24). 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 page 3-48 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.

ARM DUI 0224I Copyright © 2003-2010 ARM Limited. All rights reserved. 4-39