1. A method comprising: for a model including blocks, where, in execution, a first set of blocks is to be executed at one or more predetermined rates and a second set of blocks is to be executed at one or more parameter sample times at which one or more parameter change events occur, at least one of the parameter sample times being different from any times of execution of the first set of blocks, the first set of blocks and the second sets of blocks each comprising at least one block, generating program code, by one or more processors, for the blocks of the model, generating the program code including: generating a first set of program code for the first set of blocks, and generating a second set of program code for the second set of blocks, where the second set of program code has an entry point separate within the program code generated for the blocks of the model and from the first set of program code, and where the second set of program code comprises at least one variable usable by the first set of program code.