1. A data cache memory control system having a main memory, a data cache memory in which part of said main memory is copied, and a central processing unit (CPU) for accessing said main memory and said data cache memory, comprising: data cache memory allocating means for allocating at least a global area for storing global parameters and a local area for storing localparameters in said data cache memory, the global area being accessed in any one of a plurality of modules constituting a program, and the local area being accessed in a specific module, said CPU writing global parameters in the global area and said main memory, and reading the global parameters from said main memory when the global parameters are not found in the global area; local area access detecting means for detecting whether an access to the local area is performed; and memory access means for permanently inhibiting contents of the local area from being written into said main memory when the access to the local area is performed, and means for writing the local parameters only in the local area.