It is fundamentally possible.
However, FWP(FEW) pins are the pins to protect the incorrect write/erase to the on-chip flash with hardware.
When switching FWP(FEW) pins by the I/O port control with software, it is possible that on-chip flash can be rewritten /erased unexpectedly because of false operation of CPU, software bugs, and so on. Therefore, please make a system design after examining it enough.
|SH7052, SH7053, SH7054|
|SH7047, SH7049, SH7105, SH7107, SH7109|
|SH7046, SH7148, SH7101, SH7048, SH7104, SH7106, SH7108|
|SH7040, SH7041, SH7042, SH7043, SH7044, SH7045|
|SH7014, SH7016, SH7017|