https://www.datasheetq.com/RTL8196C-doc-Realtek

General Description The RTL8196C is an integrated System-on-a-Chip (SoC) Application Specific Integrated Circuit (ASIC) that implements a basic L2 5-port Ethernet switch and a high performance CPU. The embedded RISC CPU is an RLX4181, and the clock rate can be up to 400MHz. To improve computational performance, a 16-Kbyte I-Cache, 8-Kbyte D-Cache, 16-K I-MEM, and 8-Kbyte D-MEM are provided. A standard 5-signal P1149.1 compliant EJTAG test interface is supported for CPU testing and software development.