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Read/Write Test pattern Control Register from External hardware

Altera_Forum
Honored Contributor II
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My current project uses external microprocessor (TI MSP430) to communicate with the VIP block. As for a beginner I tried out the Test Pattern since there were only four registers to work with -- just for the sake of simplicity. However, I have not been able to read or write any of the registers at all. They are always read back all zero's.  

 

Question for your experts out there, do I need to do something special in order to get access to these registers?  

 

Here are the steps coded in my external CPU: 

 

Writing: 

• Set Register# (control_av_address[1..0]) 

• Put data on the data bus (control_av_writedata[15..0]) 

• Write Pulse HI (control_av_write = 1) 

• Delay 100us 

• Write Pulse LO (control_av_write = 0) 

 

Reading: 

• Set Register# (control_av_address[1..0]) 

• Read Pulse HI (control_chipselect = 1) 

• Delay 100us 

• Read Pulse LO (control_chipselect = 0) 

• Read Data bus (control_av_readdata[15..0]) 

 

Thanks in advance, 

 

 

JIMMY
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