If you are trying to using this chip, it is often more effective to search for the "Service Manual" of the device it lives in (like a specific car ECU model) rather than the standalone IC datasheet.
: As an older "legacy" part, it is primarily available through specialty automotive electronics suppliers like Jotrin Electronics nec b58944 datasheet
: Sites like ToyotaNation or ClubLexus often have community-uploaded pinout diagrams specifically for this IC when used in ECU repairs. Quick Technical Summary Manufacturer: NEC (Renesas Electronics) If you are trying to using this chip,
After checking available archives (including the legacy NEC semiconductor databases), the part number B58944 does not appear to match NEC’s standard part numbering system for common ICs (like µPD series), transistors (2S series), or optocouplers (PS series). transistors (2S series)