The ARM1156T2F-S processor has two functional clock inputs. Externally to the processor, you must connect together CLKIN and FREECLKIN.

For details on how the clock regions are implemented, see ARM1156T2F-S and ARM1156T2-S Implementation Guide.

For the purposes of this chapter, you can ignore FREECLKIN.

All clocks can be stopped indefinitely without loss of state.

You can preconfigure the ARM1156T2F-S processor so that each clock region operates synchronously to the core clock region.