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Hi all, I hope some one can help me. I'm trying to interface to a C5402 DSK. I want to add some hardware to the board via the daughterboard interface. When I try to perform an I/O access to the daughterboard interface (i.e. write a port, say at F002) the X_A15 line seems to be inverted! I/O accesses are only valid when X_A15 is high. Let me explain better. Lets say I try to write to a device at F002. When I look at the interface with my scope, the X_A15 is high when it should be low. I.e. in this case when X_A14,13,12 are high and X_IOSTROBE' is low the X_A15 line (which is normally high) goes low!!! So in effect 0x7002 is appearing and not F002. What am I doing wrong????? Many thanks, Richard Webb. |
Daughterboard IO access and X_A15
Started by ●December 18, 2001
