Logic fabric and on-chip memory
The XC7S25-2FTGB196I packs 23,360 logic elements in 1,825 CLB slices — enough for a modest soft-core processor, a few UARTs, and some glue logic without reaching for a larger die. The 1,658,880 bits of block RAM (about 202 KB) handle small frame buffers or FIFOs, but if your design needs more than a few hundred KB of on-chip storage, the next step up in the Spartan-7 family is worth a look.
I/O and package fit
100 user I/O in a 196-ball CSBGA (15x15 mm) — the ball pitch is 1.0 mm, which is manageable on a 4-layer board with blind vias if you keep the fan-out disciplined. The 0.95 V to 1.05 V core supply means the power rail needs tight regulation; a 1.0 V ±5 % LDO or switching regulator with good transient response is the right fit.