Я, честно говоря, "купился" на эту ссылку по фразе "4 bit application circuits".
Но чего не нашел, того - не нашел. Но 4-битных устройств от Atmel здесь
просто "туева хуча":
http://www.datasheetdir.com/Microcontrollers-4bit
PS. Впрочем, в списке встречаются и не Atmel-овкие чипы...ATAR090,ATAR090 Low-current Microcontroller For Wireless Communication
The ATAR090 and ATAR890 are members of Atmels family of 4-bit single-chip micro controllers. They offer the highest integration for IR and RF data communication and remote-control. The ATAR090 and ATAR890 are suitable for the transmitter side. They ...
ATAR090-C,ATAR090-C Low-current Microcontroller For Wireless Communication
The ATAR090-C and ATAR890-C are members of Atmels family of 4-bit single-chip microcontrollers. They offer the highest integration for IR and RF data communication and remote-control. The ATAR090-C and ATAR890-C are suitable for the transmitter side. They ...
ATAM894,ATAM894 8k-flash Microcontroller
The ATAM894 is a member of the Atmels family of 4-bit single chip microcontrollers with 8K 8-bit EEPROM program memory. It is based on the 4-K MTP version ATAM893 and fully compatible with this MTP and the ROM versions ATAR090/ATAR890 and ATAR092/ATAR892. ...
