GENERAL DESCRIPTION
The ST9040is a ROM member of the ST9 family of microcontrollers, completely developed and produced by SGS-THOMSON Microelectronics using a proprietaryn-well HCMOS process.

■ Register oriented 8/16 bit CORE with RUN, WFI and HALT modes
■ Minimum instruction cycle time : 500ns (12MHz internal) Internal Memory : ROM 16K bytes RAM 256 bytes EEPROM 512 bytes
■ 224 generalpurposeregistersavailable as RAM,
■ accumulatorsor indexregisters(register file)
■ 80-pin PQFP package for ST9040Q
■ 68-lead PLCC packagefor ST9040C
■ DMA controller, Interrupt handler and Serial Peripheral Interface as standardfeatures
■ Up to 56 fully programmable I/O pins
■ Up to 8 external plus 1 non-maskableinterrupts
■ 16 bit Timer with 8 bit Prescaler, able to be used as a WatchdogTimer
■ Two 16 bit Multifunction Timers, each with an 8 bit prescaler and 13 operating modes
■ 8 channel 8 bit Analog to Digital Converter, with Analog Watchdogs and external references
■ Serial Communications Interface with asynchronous and synchronous capability
■ Rich InstructionSet and 14 Addressingmodes
■ Division-by-Zero trap generation
■ Versatile developmenttools, including assembler, linker, C-compiler, archiver, graphic oriented debuggerand hardware emulators
■ Real Time OperatingSystem
■ Windowedand OneTime ProgrammableEPROM parts available for prototyping and pre-production developmentphases
■ Pinto pincompatible with ST9036