Method of secure management of a memory space for microcontroller

A method of managing an electronic microcontroller system, the microcontroller system including: two processors with a first processor configured for execution of a nonsecure application exhibiting a nonguaranteed level of functional security and integrity, and a second processor dedicated to execution of a secure application implementing code and data, and involving a guaranteed level of functional security and integrity, the secure application to implement a security function; and a mechanism to access to a shared memory space. The first processor includes a unit for managing the memory configured to implement a write access control, to manage write access to the shared memory space, that is not modifiable when the secure application implements its security function.