Usenet.com

www.Usenet.com

Group Index

Comp Thread Archive from Usenet.com

<-- __Chronological__ --> <-- __Thread__ -->

Need help polling Console Port on MVME167



Hi, 

I have figured out how to receive bytes from the Console Serial Port 
(CD2401 Port 0) on the MVME167 using polling.  I am having trouble 
trying to send bytes also using polling.  Can someone tell me what I 
am doing wrong?  A listing of my test program is given below.  First 
I go into a polling loop to check for a transmit IRQ.  I then do a 
"Pseudo Interrupt" and I then write the byte to the Transmit FIFO.  
I then do a Transmit End-of-Interrupt by writing 0 to the TEIOR.  I 
then pause for the byte to have enough time to send.  I then cause a 
Bus Error by attempting to read from an unmapped location.  The program 
executes like expected but no character ('*' in this case) actually 
appears out of the serial port.  

Thanks

                                        ;Wait for Transmit Character IRQ
000000 1039FFF4201E     AgainW:         MOVE.B  ($FFF4201E),D0
000006 02000020                         AND.B   #$20,D0
00000A 67F4                             BEQ.B   AgainW
                        
                                        ;Pseudo Interrupt Acknowledge
00000C 4A39FFF42025                     TST.B   ($FFF42025)
                        
                                        ;Write the Byte
000012 41F9FFF45080                     LEA.L   (CD2400),A0
000018 117C002A0078                     MOVE.B  #$2A,(CDO.TDR,A0)
                        
                                        ;End of Write Interrupt
00001E 117C00000005                     MOVE.B  #$00,(CDO.TEOIR,A0)
                        
                                        ;Pause for Send
000024 223C00100000                     MOVE.L  #$00100000,D1
00002A 5381             Loop:           SUBQ.L  #1,D1
00002C 66FC                             BNE.B   Loop
                        
00002E 4AB9FFFF0000                     TST.L   ($FFFF0000)



<-- __Chronological__ --> <-- __Thread__ -->


Usenet.com



Please check out one of the premium Usenet Newsgroup Service Providers below for access to Usenet.