Semiconductor device with delay correction function

A semiconductor device comprising:

• delay amount measuring means for measuring an actual delay amount corresponding to a specified delay amount by supplying a clock signal with a known period to a plurality of delay strings, and by detecting phase variations of the clock signal which are produced through said delay strings, each of which has a delay amount determined in advance;
• two delay sections, each of which is provided as a feedback delay string of a nonoverlapping two-phase clock signal generating circuit, and is capable of freely adjusting a connection number of delay elements;
• and
• correction signal generating means for generating a correction signal for enabling each of said delay sections to correct the connection number of the delay strings such that each delay section has a desired delay amount in accordance with the actual delay amount that corresponds to the specified delay amount and is measured by said delay amount measuring means.

A semiconductor device comprising:

• an actual delay measurement section that includes a plurality of delay strings connected in series, which have a specified delay amount to bring about phase variations of a clock signal with the known period;
• measurement result holding means for sampling clock signals with the phase variations output from the individual delay strings of said actual delay measurement section at timing of a sampling clock signal, and for holding sampled results as measurement results, the sampling clock signal having a same period and phase as the input clock signal, or having a same period as the clock signal, or having a period integer multiple of the clock signal;
• changing point detecting means for detecting a first changing point of the measurement results beginning from a smallest delay of the measurement results held by said measurement result holding means;
• and
• clock signal output selection means for selecting and outputting one of the clock signals with the phase variations output from said delay strings of said actual delay measurement section in response to the changing point detected by said changing point detecting means.