Microchip PIC32 microcontroller. Made on TSMC 180nm according to change notices, but measurements of channel length show closer to 250.
IBIS model: Package made by Amkor.
Can be made at one of several fabs. One of these is TSMC Fab 11, MSL 548, EMB FLASH 1K process.
Size is approximately 4280 x 4740 μm (20.29 mm2).
Looks to be a 4-metal 250 nm process.
Interesting region in the middle of the die. Not sure what it does but provides a nice view of standard cells on lower layers.
Test points on the flash array. Probably tied to bit/word lines. Maybe used for measuring read/erase margins during characterization?
Random wiring in the middle of the die with test points
Mask rev markings
Test patterns on bottom edge
Power busing near flash with exposed vias. ~700 nm via pitch is consistent with the 220-250 nm process node.
Top left corner of SRAM array
Edge of flash array
Random standard cell region. Note large number of dummy cells. This is most likely due to their use of a cost-optimized process with less metal layers than would be necessary to route the design with more densely packed cells.