> >----- Original Message ----- >From: zzh >To: >Sent: Wednesday, March 22, 2000 4:28 PM >Subject: About rs232 on motorola mpc8260 ads board > > >> >> Hello,everyone. >> I'm trying to make the SCC1 drived rs232 port of a motorola >> mpc8260 ads board work.The manual says it can direct connect >> to pc com port.But it seems the output from this board is not >> rs232 voltage.i.e -3 to -12 for logical one,3 to 12 for logical >> zero,nor is it TTL,it seems that it use 0 for logical 1,5.0v for >> logical 0,so it is rather annoying. I have to invert the output >> from 8260 ads,then use a TTL->232 converter to connect with PC, >> it works when i send char from 8260,but cannot work in the >> other direction. >> In addition,for a while,it output 232 signal,but i cannot >> reproduce it!! >> Does anyone has experience with this board? >> Thanks for your advice. >> davidzhang >> 3/22/2000 >> >> _____________________________________________ >> 首都在线--中国人的网上家园 http://www.263.net >> @263.net中国最大的在线邮局 http://freemail.263.net >> > > >Pavel Roskin is right , that means to check RTS(from ads) or enable it manually. > Have you hack with this board?today i check the manual,find that it has SCC1 RTS connect to rs232 CTS pin (pin 8),the init8260 program from motorola did not init this pin(PD29).Should i program this pin? How should i make the pin connection.For now,i connect DSR with DTR, Tx with PC Rx,Rx with PC tx.Most amazing to me is that when i measure the output wave from Tx pin,it is 0-5V.what it looks like when i output a 'c' (0x63 which is 01100011) is as below: start 11 000 11 0 (lsbit to msbit) 5v --- --------- --- 0v -- ------ ------ All will be right if 0v is -3 to -12 and 5v is 3 to 12 What wrong with this? >b.r. >john zhan. >hacking time. > > > > _____________________________________________ 首都在线--中国人的网上家园 http://www.263.net @263.net中国最大的在线邮局 http://freemail.263.net ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/