Tentatively ID'd as UMC 180nm from CMP filler pattern.
This specimen was obtained from marshallh for failure analysis. Pins 5 and 6 are shorted together on die (verified by cutting the bond wire after live decap). Root cause unknown, pending further analysis
Fuses are visible at the upper right side of the die. Probably used for selecting the 2232H or 4232H since these appear to be the same die (no 4232H has been decapped yet, but the 2232H says 4232 on it and the pinouts/static power match up exactly).
Pin 1 is upper left. Note that some power pins, as well as the USB pair, have two bond pads per package pin.
Size is approximately 2900 x 2890 μm (8.38 mm2)
(C) FTDI 2009 - ft4232/A13
Darkfield of upper left with bond wires intact
Bond pads. Top two are GND (as is the bus ring to the right); bottom is Vref (shorted to GND for reasons unknown). No obvious failure point, will need to do FIB sectioning.
Fuse area closeup.