While a standalone "B58944" datasheet is rare because it's an OEM part number, you should search for the μPD43256B datasheet from NEC/Renesas to get full electrical timing and pinout details.

: Detailed technical parameters and pinouts can be found on platforms such as Elparts or AllDatasheet under its commercial equivalent, μPD43256BGU. B58944 - datasheet, pdf, info, parameters, stock - Elparts

The NEC B58944 is a . It was designed primarily for high-frequency amplification and switching applications. Because it was manufactured during an era of robust analog and early digital expansion, it is known for its reliability and stable thermal characteristics. Key Specifications (Typical)

Key electrical / packaging facts (compiled from distributor listings and datasheet aggregators)