SN32F280 Series
32-Bit Cortex-M0 Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 248
Version 1.1
21.8 FLASH MEMORY CONTROLLER (FMC)
The FMC handles the program and erase operations of the Flash memory.
21.8.1 CODE SECURITY (CS)
Code Security is a mechanism that allows the user to enable different levels of security in the system so that access to
the on-chip Flash and use of the ISP can be restricted.
Note: Any Code Security change becomes effective only after the MCU has been Reboot.
User ROM
CS0
CS1
CS2
Description
WRITER
Read
O
X
X
Erase
O
O(*)
O(*)
(*) WRITER will change the CS level to CS0.
Program
O
O
O
FW
(EEPROM emulation)
Read
O
O
O
Erase
O
O
O
Program
O
O
O
SWD
Read
O
X
X
Erase
O
X
X
Program
O
X
X
Note: User may try to change security level from CS3 to CS0, from CS2 to CS0, or from CS1 to CS0.
HW shall:
1. Mass erase the User ROM first. User shall NOT execute this operation in debug mode, since the
SWD communication may fail during the mass erase procedure.
2. Update security level.
CS1
CS0
CS2
includes:
- New option byte programming
includes:
- Option byte erase
- Mass Erase
