The MC9S12D is a 16-bit MCU composed of standard on-chip peripherals, including: Two asynchronous serial communications interfaces 8-channel IC/OC enhanced capture timer Two 8-channel, 10-bit analog-to-digital converters (ADC) 8-channel pulse-width modulator (PWM) 20 discrete digital I/O lines Inter-IC Bus System resource mapping, clock generation, interrupt control and bus interfacing are managed by the System Integration Module (SIM). The MC9S12D has full 16-bit data paths throughout. However, the external bus can operate in an 8-bit narrow mode so single 8-bit wide memory can be interfaced for lower cost systems. A PLL circuit allows power consumption and performance to be adjusted.Upward compatible with M68HC11 instruction setInterrupt stacking and programmer's model identical to M68HC11Instruction pipeEnhanced indexed addressingMemory:Until 512 Kbyte Flash EEPROMuntil 4 Kbyte EEPROMUntil 12 Kbyte RAM