When you use CMD27 you must only change the writable part of the CSD. The other data must match the read only part in the CSD.
You must use the correct value for the CRC field in the register.
These are the three bits you can change but only TMP_WRITE_PROTECT can changed back.
• COPY
Defines whether the contents is original (=0) or has been copied (=1). Setting this bit to 1 indicates that
the card content is a copy. The COPY bit is a one time programmable bit except ROM card.
• PERM_WRITE_PROTECT
Permanently protects the entire card content against overwriting or erasing (all write and erase
commands for this card are permanently disabled). The default value is 0, i.e. not permanently write
protected.
• TMP_WRITE_PROTECT
Temporarily protects the entire card content from being overwritten or erased (all write and erase
commands for this card are temporarily disabled). This bit can be set and reset. The default value is 0,
i.e. not write protected.