Unknown 16-pin bare die found in my lab while imaging backlog. No idea of function, vendor, or original markings.

Preliminary analysis:

• 1-metal 1-poly CMOS process
• Large “herringbone” structures are pad drivers
• Pad with trimmed corners is #1
• Pad above it is #16, Vdd
• Pad second from bottom on right is #8, Vss
• Inner ring is Vss
• Outer ring is Vdd
• Best guess so far is loadable 4-bit up/down counter, maybe 74HC or CD4000 series