“The identification is Sega part # 315-5744, Hitachi part # HD404920FS from a Saturn. Programming manuals refer to it as the SMPC.”
Allegedly a 4-bit microcontroller. Possibly related to the HD404918/HD404919? Those would have 8k/16k-word x 10 bit ROMs.
Package
SEGA 315-5744-A05 HD40920FS 5E1 JAPAN
