I tested and deployed two AT89LP4052 parts in DIP-20 packages. One part went into a prototype RF receiver module that displays a clock that gets real time clock correction updates once per minute through a short haul 434MHz RF link. In this device I replaced a former AT89C4051. The coding for that is all in assembler language and the new parts work well. I did have to change the crystal frequency because the 'LP4052 can only go to 20MHz. The clock on this device displays on an 8-digit display made with big 7 segment displays driven by a shift register driver that is 64 bits long.

The second part went into a derivative display device that uses eight 16-segment displays. It receives the same RF update signal but then makes the clock display by creating a 128 bit serial bit stream to the shift register display drivers. It uses a modification of the assembler code set from the first described device.

Both display devices are built on proto board type construction and have soldered in 8-pin headers that let me program the AT89LP4052s via one of the ASIX Presto USB serial programmers. Works like a champ.

Even at 20MHz these small MCUs are competing closely with parts such as the SiLabs C8051F226 albeit with lower pin count than the SiLabs part.

Michael Karas