Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO データシート
製品コード
ATSAM4E-XPRO
409
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
Calibration bits can be read by the software application in EEFC_FRR. The first word read corresponds to
the first 32 calibration bits. The following reads provide the next 32 calibration bits as long as it is meaningful.
Extra reads to EEFC_FRR return 0.
the first 32 calibration bits. The following reads provide the next 32 calibration bits as long as it is meaningful.
Extra reads to EEFC_FRR return 0.
The 4/8/12 MHz fast RC oscillator is calibrated in production. This calibration can be read through the Get CALIB
bit command. The table below shows the bit implementation for each frequency:
bit command. The table below shows the bit implementation for each frequency:
Table 21-5.
Calibration Bit Indexes
The RC calibration for the 4 MHz is set to ‘1000000’.
21.4.3.7 Security Bit Protection
When the security is enabled, access to the Flash, either through the JTAG/SWD interface or through the Fast
Flash Programming interface, is forbidden. This ensures the confidentiality of the code programmed in the Flash.
Flash Programming interface, is forbidden. This ensures the confidentiality of the code programmed in the Flash.
The security bit is GPNVM0.
Disabling the security bit can only be achieved by asserting the ERASE pin at 1, and after a full Flash erase is
performed. When the security bit is deactivated, all accesses to the Flash are permitted.
performed. When the security bit is deactivated, all accesses to the Flash are permitted.
21.4.3.8 Unique Identifier
Each part is programmed with a 128-bit unique identifier. It can be used to generate keys for example. To read the
unique identifier, the sequence is:
unique identifier, the sequence is:
Send the Start read unique identifier command (STUI) by writing EEFC_FCR with the STUI command.
When the unique identifier is ready to be read, the FRDY bit in EEFC_FSR falls.
The unique identifier is located at the address 0x00400000-0x004003FF, in the first 128 bits of the Flash
memory mapping.
memory mapping.
To stop the unique identifier mode, the user needs to send the Stop read unique identifier command (SPUI)
by writing EEFC_FCR with the SPUI command.
by writing EEFC_FCR with the SPUI command.
When the SPUI command has been performed, the FRDY bit in EEFC_FSR rises. If an interrupt was
enabled by setting the FRDY bit in EEFC_FMR, the interrupt line of the interrupt controller is activated.
enabled by setting the FRDY bit in EEFC_FMR, the interrupt line of the interrupt controller is activated.
Note that during the sequence, the software cannot run out of Flash.
21.4.3.9 User Signature
Each part contains a user signature of 512-bytes. It can be used for storage. Read, write and erase of this area is
allowed.
allowed.
To read the user signature, the sequence is as follows:
Send the Start read user signature command (STUS) by writing EEFC_FCR with the STUS command.
When the user signature is ready to be read, the FRDY bit in EEFC_FSR falls.
The user signature is located in the first 512 bytes of the Flash memory mapping, thus, at the address
0x00400000-0x004001FF.
0x00400000-0x004001FF.
To stop the user signature mode, the user needs to send the Stop read user signature command (SPUS) by
writing EEFC_FCR with the SPUS command.
writing EEFC_FCR with the SPUS command.
When the SPUI command has been performed, the FRDY bit in EEFC_FSR rises. If an interrupt was
enabled by setting the FRDY bit in EEFC_FMR, the interrupt line of the interrupt controller is activated.
enabled by setting the FRDY bit in EEFC_FMR, the interrupt line of the interrupt controller is activated.
Note that during the sequence, the software cannot run out of Flash or the second plane in case of dual plane.
RC Calibration Frequency
EEFC_FRR Bits
8 MHz output
[28 - 22]
12 MHz output
[38 - 32]