identify Sigma Designs chips

Sigma Designs Inc. [PCI vendor ID 1105]
Sigma Designs Corp [PCI vendor ID 1236]

dl $ info EM8220 EM8220	dl $ info EM8300 EM8300	dl $ info EM8475 EM8475

EM8220 MPEG-2 / DVD decoder
[8300] EM8300 REALmagic 64/GX (64 bit, 1-4MB RAM)
[0000] REALmagic 64/GX
[6401] REALmagic 64/GX (SD 6425)
EM8475 A/V Streaming Processor