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Bootloader protocol version evolution

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Bootloader protocol version evolution

Table 3 lists the bootloader versions.

Table 3. Bootloader protocol versions

Version

Description

V2.0

Initial bootloader version.

V2.1

– Update Go command to initialize the main stack pointer

– Update Go command to return NACK when jump address is in

the Option byte area or System memory area

– Update Get ID command to return the device ID on two bytes

– Update the bootloader version to V2.1

V2.2

– Update Read Memory, Write Memory and Go commands to

deny access, with a NACK response, to the first bytes of RAM

memory used by the bootloader

– Update Readout Unprotect command to initialize the whole RAM

content to 0x0 before RDP disable operation

V3.0

– Extended Erase command added to support number of pages

larger than 256 and separate bank mass erase.

– Erase command has not been modified in this version but, due to

addition of the Extended Erase command it is no longer

supported (Erase and Extended Erase commands are

exclusive).

V3.1

– Limitation fix of:

“When a Read Memory command or Write Memory command is

issued with an unsupported memory address and a correct

address checksum (ie. address 0x6000 0000), the command is

aborted by the bootloader device, but the NACK (0x1F) is not

sent to the host. As a result, the next 2 bytes (which are the

number of bytes to be read/written and its checksum) are

No changes in specification, the product implementation has

been corrected.

1.

If the “number of data - 1” (N-1) to be read/written is not equal to a valid command code (0x00, 0x01,

0x02, 0x11, 0x21, 0x31, 0x43, 0x44, 0x63, 0x73, 0x82 or 0x92), then the limitation is not perceived from

the host since the command is NACKed anyway (as an unsupported new command).