Finding a complete datasheet for the can be tricky as it is an older integrated circuit (IC) primarily used in specialized automotive or consumer electronics.
Integrated circuits > Memories > SRAM > Parallel. eq. μPD43256BGU-70L. NEC Electronics. SO-28. Size = 256 Kib. NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC nec b58944 datasheet
Extensive searches of Renesas’s public archive and major datasheet aggregators suggest that the B58944 is likely a custom ASIC (Application-Specific Integrated Circuit) . This means NEC designed it for a particular OEM customer (e.g., Sony, Panasonic, JVC, or a car manufacturer). Therefore, a single, universally standard datasheet may not exist in public databases. Finding a complete datasheet for the can be
The NEC B58944 datasheet represents a classic challenge in legacy electronics repair: a custom, often undocumented ASIC from a defunct product line. While you may never find a pristine 20-page PDF from NEC, this guide provides the next best thing—a functional understanding of its likely electrical parameters, pinout logic, and most importantly, a systematic search strategy. μPD43256BGU-70L
: For repair-ready chips, retailers like ECUFixTool or Inovauto provide versions specifically for board-level repairs. NEC B58944 ECU DRIVER SOP-28 - Inovauto.com NEC B58944 ECU DRIVER SOP-28. Inovauto.com B58944 - datasheet, pdf, info, parameters, stock - Elparts