XC3S100E_06 Datasheet, PDF (43/231 Pages) Xilinx, Inc – Configurable Logic Block (CLB)

R
Functional Description
Data_in
Internal
DI _Memory
DO
No change during write
CLK
WE
DI
XXXX
1111
2222
XXXX
ADDR
aa
bb
cc
dd
DO
0000
MEM(aa)
MEM(dd)
EN
DISABLED
READ
WRITE
MEM(bb)=1111
WRITE
MEM(cc)=2222
READ
DS312-2_07_020905
Figure 35: Waveforms of Block RAM Data Operations with NO_CHANGE Selected
Setting the WRITE_MODE attribute to a value of
NO_CHANGE, puts the DO outputs in a latched state when
asserting WE. Under this condition, the DO outputs retain
the data driven just before WE is asserted. NO_CHANGE
timing is shown in the portion of Figure 35 during which WE
is High.
DS312-2 (v3.4) November 9, 2006
www.xilinx.com
43
Product Specification