Work With Flash Memory - Digi XBee 868LP User Manual

Advanced application features
Byte offset Number of
in payload bytes
2 2*
4 2*
6 2*
8 varies
* Specify multi-byte parameters with big-endian byte ordering.
When a device sends a GPM command to another device via a unicast, the receiving device sends a
unicast response back to the requesting device's source endpoint specified in the request packet. It
does not send a response for broadcast requests. If the source endpoint is set to the DIGI_DEVICE
endpoint (0xE6) or Explicit API mode is enabled on the requesting device, then the requesting node
outputs a GPM response as an explicit API RX indicator frame (assuming it has API mode enabled).
The format of the response is similar to the request packet:
Byte offset in
payload
0
1
2
4
6
8
* Specify multi-byte parameters with big-endian byte ordering.

Work with flash memory

When working with the General Purpose Memory, observe the following limitations:
Flash memory write operations are only capable of changing binary 1s to binary 0s. Only the
n
erase operation can change binary 0s to binary 1s. For this reason, you should erase a flash
block before performing a write operation.
When performing an erase operation, you must erase the entire flash memory block—you
n
cannot erase parts of a flash memory block.
XBee 868LP RF Modules User Guide
Field name
GPM_BLOCK_NUM
GPM_START_INDEX
GPM_NUM_BYTES
GPM_DATA
Number of
bytes Field name
1 GPM_CMD_ID
1 GPM_STATUS
2* GPM_BLOCK_NUM
2* GPM_START_INDEX
2* GPM_NUM_BYTES
varies GPM_DATA
General Purpose Flash Memory
General field description
The block number addressed in the
GPM.
The byte index within the addressed
GPM block.
The number of bytes in the GPM_DATA
field, or in the case of a READ, the
number of bytes requested.
General field description
This field is the same as the
request field.
Status indicating whether the
command was successful.
The block number addressed in
the GPM.
The byte index within the
addressed GPM block.
The number of bytes in the GPM_
DATA field.
111