Answers Database

M1.5 EPIC: How to read the CLB carry mode


Record #2213

Product Family:  Software

Product Line:  FPGA Implementation

Problem Title:
M1.5 EPIC: How to read the CLB carry mode


Problem Description:
Keywords: carry logic, epic

Urgency:  Standard

General Description:

How do I determine a CLB's carry mode in EPIC?


Solution 1:

Select the CLB in EPIC, then click Editblock.  In the Editblock screen, select C
arry.  The CLB carry mode will be highlighted in the list of possible carry mode
s.

You can also determine the carry mode directly from the CLB diagram in Editblock
:

1. The carry function type (e.g., ADD or ADDSUB) is selected from the list in th
e in the CARRYMODE entity.

2. The function generators used by the carry mode (F, G, or FG) have the CARRY c
heck box filled in.

3. The carry source (e.g., 0, 1, or CI) is indicated by the corresponding select
ed input on the 6-to-1 carry mux.

In the example Editblock screen shot below, the ADDSUB function is selected (1),
 both F and G carry blocks are active (2), and the CI input is active on the car
ry mux (3).  This indicates that the carry mode is ADDSUB-FG-CI.


CLB Configured as ADDSUB-FG-CI



End of Record #2213