Joson,

The DUART is a well known part search the web and you will find lots of ref's.

8051 connects:

Data Bus connects to d0-d7 (pin#22-#7). A0-2 connect to a0-a2 (pin#8-#6) if you aren't using an address de-muxer ('373/'573) then connect a0-a2 to port pins and bit-bang the address. CEN is either decoded or another port pin for activation. The WRN/RDN are 8051 compatible (P3.6 p3.7). RESET would be a port pin. INTRN is 8051 compatible (p3.2/.3) and use a pull-up (10-47K).

check out:


http://www.philipslogic.com/support/a.../an405.pdf


regards,
p