| 摘要 |
PROBLEM TO BE SOLVED: To restrain influence of a deteriorated signal waveform to minimum and enable stable operation at high speed, by assigning an external connecting terminal for a reference clock signal having the shortest signal rise time and signal fall time to an external connecting terminal which is nearest to the outer periphery of a package. SOLUTION: In order to reduce deterioration of a signal to minimum, the rise time and the fall time of a reference clock signal CLK are made shorter than those of a data signal DATA synchronous with the reference clock signal CLK, so that a signal wiring transmitting the reference clock signal CLK whose signal deterioration is smallest is assigned to a wiring 151 having the shortest plated wiring stub 161. A signal wiring transmitting the data signal DATA whose rise time or fall time is longer than that of the reference clock CLK is assigned to a wiring 152 having a plated wiring stub 162, whose length is greater than or equal to that of the plated wiring stub 161. |
