US 11,055,237 B2
Method of access to a memory
Layachi Daineche, Boue-bel-Air (FR); Xavier Chbani, Grenoble (FR); and Nadia Van-Den-Bossche, Meylan (FR)
Assigned to STMicroelectronics (Rousset) SAS, Rousset (FR); and STMicroelectronics (Grenoble 2) SAS, Grenoble (FR)
Filed by STMicroelectronics (Rousset) SAS, Rousset (FR); and STMicroelectronics (Grenoble 2) SAS, Grenoble (FR)
Filed on Oct. 7, 2019, as Appl. No. 16/594,210.
Claims priority of application No. 1871152 (FR), filed on Oct. 9, 2018.
Prior Publication US 2020/0110713 A1, Apr. 9, 2020
Int. Cl. G06F 21/79 (2013.01); G06F 12/14 (2006.01); G06F 9/4401 (2018.01); G06F 21/62 (2013.01)
CPC G06F 12/1458 (2013.01) [G06F 9/4403 (2013.01); G06F 21/6218 (2013.01); G06F 21/79 (2013.01); G06F 2212/1052 (2013.01)] 30 Claims
OG exemplary drawing
 
1. A method, comprising:
configuring a non-volatile memory of a microcontroller to include a secure memory area and a non-secure memory area;
storing a protection variable in the non-volatile memory, said protection variable having a value selected from among at least four values, wherein each value of the at least four values specifies conditions for accessing the secure memory area and non-secure memory area based on a level of security for the access and a source of the access; and
conditioning access by said source to the non-volatile memory based on the value of the protection variable stored in the non-volatile memory;
wherein when the protection variable has a fourth value, said conditioning comprises, if the source of the access is a debugger connected to the microcontroller, blocking access to data buses connected to the non-volatile memory.