The Dingoo A-320 uses an undocumented chipset, but is believed to be a modified Jz4740.
Ingenic seems to say that it is a Jz4740 meant for exportation outside China.
The processor itself is identified as 0x0AD0024F (which is the same as the Jz4740)
This is the Jz4740 32 Bits Microprocessor Datasheet