We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi,
I am using C8051F120 from Silabs.., I have connected PPI 8255 with my controller which is be addressed as External Memory interface(EMI) as I take control lines of PPI A0,A1 with lower ports of Microcontroller..
I am finding problem with interfacing using XBYTE to address externaly..,
Ex:
XBYTE[0x0000]=0xFF;
where the control lines of PPI A0,A1 r selected with address XBYTE[0x0000] and data is latched with 0xFF;
this operation is not performed properly..,
If there is any solution to this problem.. plz let me know...
Rajesh
The 8255 is a really old and slow peripheral, and the C8051F120 is one of the latest, whizziest 8051s - it's a bit bizarre to be using them together!
Anyhow, with the above in mind, are you sure that the timing on the C8051F120's External Memory interface is compatible with the 8255?
Is the EMI correctly enabled & configured?