Maxim Integrated MAXQ20-Based Microcontroller Bootloader Command Reference - Manual (Page 9)

MAXQ20-Based Microcontroller Bootloader Command Reference
9
Family 3 Commands—CRC Variable Length
Command 30h—CRC Code Variable Length
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8
Byte9
Input
(to CRC
< 256 units)
30h 1 AddrL AddrH
Lengt
h
00h 00h 00h 00h
Output CrcH CrcL 03Eh
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8 Byte9 Byte10
Input
(to CRC
256+ units)
30h 2 AddrL AddrH LenL LenH 00h 00h 00h 00h
Output CrcH CrcL 03Eh
This command has a slightly different format depending on the length of the CRC requested. It returns the CRC-
16 value (CrcH:CrcL) of the program flash – (Length) or (LenH:LenL) bytes/words starting at (AddrH:AddrL).
“Units” is either bytes or words, depending on which mode is currently selected.
Command 31h—CRC Data Variable Length
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8
Byte9
Input
(to CRC
< 256 units)
31h 1 AddrL AddrH Length 00h 00h 00h 00h
Output CrcH CrcL 03Eh
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7 Byte8 Byte9 Byte10
Input
(to CRC
256+ units)
31h 2 AddrL AddrH LenL LenH 00h 00h 00h 00h
Output CrcH CrcL 03Eh
This command has a slightly different format depending on the length of the CRC requested. It returns the CRC-
16 value (CrcH:CrcL) of the data SRAM – (Length) or (LenH:LenL) bytes/words starting at (AddrH:AddrL). “Units”
is either bytes or words, depending on which mode is currently selected.