I am Vigita S. a Device Support Engineer from BPM Microsystems.
I am currently working on the device UCD90120RGCR. I am able to read the device using the command FDh.
From the "Configuration Programming of UCD Devices.pdf", I understand that before programming the data flash area, we need to unlock the flash and erase it. And the command I get from the above mentioned pdf is, BlockWrite,0x7E,0xE2,0x050400000104 followed by BlockWrite,0x7E,0xE3,0x0400008820