Datasheet
392
XMEGA B [DATASHEET]
8291B–AVR–01/2013
writing data or program memory addresses from the PDI refer to the memory map shown in Figure 30-3 on page 391.
The PDI uses byte addressing, and hence all memory addresses must be byte addresses. When filling the flash or
EEPROM page buffers, only the least-significant bits of the address are used to determine locations within the page
buffer. Still, the complete memory mapped address for the flash or EEPROM page is required to ensure correct address
mapping.
During programming (page erase and page write) when the NVM is busy, the NVM is blocked for reading.
30.12.3 NVM Commands
The NVM commands that can be used for accessing the NVM memories from external programming are listed in Table
30-5 on page 392. This is a superset of the commands available for self-programming.
For external programming, the trigger for action-triggered commands is to set the CMDEX bit in the NVM CTRLA register
(CMDEX). The read-triggered commands are triggered by a direct or indirect load instruction (LDS or LD) from the PDI
(PDI read). The write-triggered commands are triggered by a direct or indirect store instruction (STS or ST) from the PDI
(PDI write).
“ Chip Erase” on page 393 through “ Write Fuse/ Lock Bit” on page 395 explain in detail the algorithm for each NVM
operation. The commands are protected by the lock bits, and if read and write lock is set, only the chip erase and flash
CRC commands are available.
Table 30-5. NVM commands available for external programming.
CMD[6:0] Commands / Operation Trigger
Change
Protected
NVM Busy
0x00 No operation - - -
0x40 Chip erase
(1)
CMDEX Y Y
0x43 Read NVM PDI Read N N
Flash Page Buffer
0x23 Load flash page buffer PDI Write N N
0x26 Erase flash page buffer CMDEX Y Y
Flash
0x2B Erase flash page PDI write N Y
0x2E Write flash page PDI write N Y
0x2F Erase and write flash page PDI write N Y
0x78 Flash CRC CMDEX Y Y
Application Section
0x20 Erase application section PDI write N Y
0x22 Erase application section page PDI write N Y
0x24 Write application section page PDI write N Y
0x25 Erase and write application section page PDI write N Y
0x38 Application section CRC CMDEX Y Y
Boot Loader Section
0x68 Erase boot section PDI write N Y
0x2A Erase boot loader section page PDI write N Y
0x2C Write boot loader section page PDI write N Y
0x2D Erase and write boot loader section page PDI write N Y