Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Highlighted
Valued Contributor III
840 Views

Using OLD_DATA with 'tightly coupled memory'

We are moving a project forward to quartos 14.1 (and new hardware). 

The qsys page for 'On-Chip memory' now lets you select single clock in order to get true dual port and OLD_DATA. 

However there is a comment that 'Tightly Coupled Memory operation requires dual port & dual clock sources. 

 

Lack of 'OLD_DATA' gave us grief on 9.1 and we fixed it by editing the memory wrapper. 

 

Does anyone know if this is still a bug/restriction in qsys, or is the comment wrong. 

 

IIRC the tightly coupled memory uses the 'address_stall' to hold the output data during 

pipeline stalls. This seems to be defined for the Cyclone V we are targetting.
0 Kudos
1 Reply
Highlighted
Valued Contributor III
7 Views

Where did you see the comment on the Tightly Coupled Memory ....?  

 

You can just set dual port and single clock mode. It should work with old data.
0 Kudos