Integrated circuits > Memories > SRAM > Parallel. eq. μPD43256BGU-70L. NEC Electronics. SO-28. Size = 256 Kib. NEC B58944 D43256BGU-70Y BOSCH Auto ECU computer IC
This chip is a critical component for data storage and processing in older automotive systems. Automotive ECUs
Companies like (authorized obsolete semiconductor supplier) or UTSOURCE may have the datasheet or die information as part of their inventory records. nec b58944 datasheet
: Because these chips are prone to failure in harsh automotive environments (heat/vibration), they are often sought as replacement parts for repairing "bricked" or malfunctioning engine control modules. Sourcing and Data Manufacturer : Originally produced by NEC Corporation , now under the Renesas Electronics portfolio. Availability
Based on cross-referencing similar NEC part numbers (e.g., B589XX series), the B58944 is most likely one of the following: Integrated circuits > Memories > SRAM > Parallel
: Frequently found on Bosch automotive engine boards as a "vulnerable" part prone to failure.
The NEC B58944 is a critical component for technicians specializing in . It typically functions as a "driver chip" or temporary data storage within the engine computer. NEC Electronics
Because of this evolution, finding the can sometimes be a challenge. The document may be archived under legacy databases or cross-referenced under Renesas part numbers. For engineers, this highlights the importance of preserving and understanding these documents, as they are essential for maintaining equipment that was designed and built decades ago but is still vital to current operations.
Finding a datasheet for the can be tricky because it is primarily an automotive-grade integrated circuit (IC) often used in Bosch Engine Control Units (ECUs). It is widely recognized in the automotive repair industry as an equivalent to the µPD43256BGU-70L or µPD43256BGU-70Y , which is a 256 Kbit Parallel Static RAM (SRAM). Core Specifications: NEC B58944 / µPD43256B
Without the original OEM schematic, we can make educated guesses from pinout patterns (see below).
Specifically in older Toyota and Lexus models to manage fuel injection or ignition timing.