METHOD FOR OPERATING PROGRAMMABLE LOGIC DEVICE

In a multi-context PLD (dynamically reconfigurable circuit), at the tune of rewriting configuration data on a non-selected context during circuit operation, configuration data is stably stored. At the time of rewriting configuration data on a non-selected context, writing to a row which is to be rewritten continues until input signals supplied to input terminals of routing switches in the row become “L” all that time or the input signals become “L” at least once. More specifically, a write selection signal for the row continues to be output. In addition, while the write selection signal is being output, loading of configuration data into a driver circuit is not conducted, or loading of configuration data into a driver circuit is conducted but storage thereof in a line buffer is not conducted.