The document describes the Motorola MC68705R3, a low-cost 8-bit EPROM microcontroller unit (MCU) belonging to the MC6805 family. It features an internal timer with a programmable prescaler, on-chip oscillator, vector interrupts, and a bootstrap program in ROM.
The MCU includes 12 bytes of RAM and 3776 bytes of user-programmable EPROM. It offers versatile interrupt handling, bit manipulation capabilities, and a 4-channel analog-to-digital converter. The device supports 24 I/O pins arranged into four ports (A, B, C, and D), with Port D providing fixed input functionality including analog inputs.
The maximum recommended capacitance (Co) for a crystal oscillator is 7 pF.
The device includes 3776 bytes of user EPROM memory.