Dynamic clock change circuit
View Patent ↗A clock change circuit includes enabling a clock change frequency to be accepted while a system is active and clock frequencies are at a low period. The circuit includes generating an enabling signal representing a window of time in which a frequency change is accomplished.
1. A clock frequency change circuit comprising:
a synchronous counter for receipt of a master clock signal;
a first multiplexer for receipt of an output of the counter, the first multiplexer outputting a clock frequency to a first system clock;
a second multiplexer for receipt of the output of the counter, the second multiplexer outputting a clock frequency to a second system clock; and
a flip flop for generating an enable signal corresponding to a low frequency period of the master clock signal and for enabling a clock change request signal.
2. The circuit of claim 1 wherein the synchronous counter is a 5-bit counter.
3. The circuit of claim 1 further comprising a NOR gate disposed between the counter and the flip flop.
4. The circuit of claim 1 wherein the output of the counter is a frequency signal is divided by an integer value.
5. The circuit of claim 4 wherein the integer value is selected from a group consisting of 2, 4, 8, 16 and 32.