Simulator and simulation method

A simulator comprising:

• a first core unit corresponding to a first simulation model;
• a second core unit corresponding to a second simulation model different from the first simulation model, the first simulation model being a model for simulating with higher precision than the second simulation model, the second simulation model being a model for simulation at a higher speed than the first simulation model;
• a data copy control unit connected between the first core unit and the second core unit;
• a slave block unit that communicates with either the first core unit or the second core unit;
• and
• a simulation control unit for making either the first core unit or the second core unit execute instructions,
• wherein the first core unit includes:
• an instruction execution unit for executing a program for the first simulation model while updating a program counter;
• an instructions execution control unit for controlling the instructions unit execution unit;
• a data unit for receiving data that is generated when the program is executed;
• a high speed mode instruction execution control unit that, in response to receiving a switching request for switching from the first simulation model to the second simulation model, taking over a role of controlling the instructions execution unit from the instructions execution control unit to stop subsequent instructions from being executed;
• and
• a transaction monitor unit for monitoring whether all transaction processing between the first core unit and the slave block unit is completed or not,
• wherein, in response to receiving a notification of completion of all transaction processing from the transaction monitor unit, the simulation control unit instructs the data copy control unit to copy data in the data unit of the first core unit to a data unit of the second core unit, and
• wherein, in response to receiving from the data copy control unit a notification of completion of copying the data from the data unit of the first core unit to the data unit of the second core unit, the simulation control unit causes the second core unit to execute instructions.