Decapped random chip - Microchip PIC16LC72A

This time I've decapped a Microchip PIC16LC72A, an 8-bit PIC microcontroller chip.

The chip is in SOIC-28 package and is the LC variant which supports lower VDD voltage than the normal C variant. Based on the package marking information described in the datasheet, the chip is from year 2000 week 50.

Here's the raw die after decapping (click for max resolution photo. Warning: it's 16MB):

This photo was captured using my "Frankenscope", and is licensed under Creative Commons Attribution 4.0 International.

This die has 33 bonding pads with wires but the package has only 28 pins. The datasheet specifies that some pins change their input buffer type (e.g. Schmitt Trigger / CMOS / TTL) depending on the currently selected function. Perhaps in these cases the external pin connects to two separate pads with different input buffer structures.