Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet
Product codes
ATSAM4S-WPIR-RD
379
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
In the same way, the Clear GPNVM command (CGPB) is used to clear general-purpose NVM bits. The general-
purpose NVM bit is deactivated when the corresponding bit in the pattern value is set to 1.
General-purpose NVM bits can be read using the Get GPNVM Bit command (GGPB). The n
th
GP NVM bit is
active when bit n of the bit mask is set..
21.3.5.6 Flash Security Bit Command
A security bit can be set using the Set Security Bit command (SSE). Once the security bit is active, the Fast Flash
programming is disabled. No other command can be run. An event on the Erase pin can erase the security bit
once the contents of the Flash have been erased.
Once the security bit is set, it is not possible to access FFPI. The only way to erase the security bit is to erase the
Flash.
In order to erase the Flash, the user must perform the following:
In order to erase the Flash, the user must perform the following:
Power-off the chip
Power-on the chip with TST = 0
Assert Erase during a period of more than 220 ms
Power-off the chip
Then it is possible to return to FFPI mode and check that Flash is erased.
21.3.5.7 Memory Write Command
This command is used to perform a write access to any memory location.
Table 21-11.
Set/Clear GP NVM Command
Step
Handshake Sequence
MODE[3:0]
DATA[
15
:0]
1
Write handshaking
CMDE
SGPB or CGPB
2
Write handshaking
DATA
GP NVM bit pattern value
Table 21-12.
Get GP NVM Bit Command
Step
Handshake Sequence
MODE[3:0]
DATA[
15
:0]
1
Write handshaking
CMDE
GGPB
2
Read handshaking
DATA
GP NVM Bit Mask Status
0 = GP NVM bit is cleared
1 = GP NVM bit is set
0 = GP NVM bit is cleared
1 = GP NVM bit is set
Table 21-13.
Set Security Bit Command
Step
Handshake Sequence
MODE[3:0]
DATA[
15
:0]
1
Write handshaking
CMDE
SSE
2
Write handshaking
DATA
0