7540 - SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
7540 Features
* Basic machine-language instructions 71
* The minimum instruction execution time 0.50 µs (at 8 MHz oscillation frequency for the shortest instruction)
* Memory size ROM 16K to 32K bytes RAM 512 to 768 bytes
* Programmable I/O ports 29 (25 in 32-pin version)