FT232RL USB-serial converter packaged in 28-SSOP. Most likely the same die as the FT232RQ (QFN) however this has not been confirmed.
The FT232R has on-board EEPROM for descriptors and a pre-programmed unique serial number, as opposed to most of FTDI's other devices which require external EEPROMs.
We were curious as to whether the FT232R was just a USB MCU like the Microchip MCP2200, or a pure ASIC. The lack of obvious ROM areas suggest that it is indeed an ASIC. FIB cross section suggests technology node is around 600 nm with 3 metal layers.
Full die overview
Memory banks. Probably EEPROM on left and SRAM at right.
Logic cell area.