GENERAL DESCRIPTION

The ST90E27, E28 and ST90T27, T28 (following mentioned as ST90E2x) are EPROM members of the ST9 family of microcontrollers, in windowed ceramic (E) and Plastic OTP (T) packages respectively, completely developed and produced by SGS-THOMSON Microelectronics using a n-well proprietary HCMOS process.

The EPROM parts are fully compatible with their ROM versions and this datasheet will thus provide only information specific to the EPROM based devices.