http://www.cpubenchmark.net/cpu.php?cpu=AMD+A4-3420+APU
According to this article, that is an APU from the "Llano" series (intended for inexpensive systems, such as "NetTop" class PCs, not full-power PCs). The included GPU, integrated into the APU, was supposed to be an HD 6410.
http://www.cpu-world.com/CPUs/K10/AMD-A4-Series%20A4-3420.html