SD/MMC card - must I erase before write?

[Chlopczyk]

Besides read and write commands, the SD and MMC cards have ERASE
commands. Doest it mean that I have to execute the ERASE command
before I write something to an already written block? Or can I
overwrite directly?

If the ERASE command is necessary, what can be consequences of
forgetting about it? Only corrupted data or damage to the card?

 

[Ian Stirling]

Besides read and write commands, the SD and MMC cards have ERASE
commands. Doest it mean that I have to execute the ERASE command
before I write something to an already written block? Or can I
overwrite directly?

Overwrite directly.

If the ERASE command is necessary, what can be consequences of
forgetting about it? Only corrupted data or damage to the card?

Erase is for when you want to delete a block, but not write anything
to it, and leave it in a state where it doesn't need (automatically)
erased before writing again.