at94k40al ATMEL Corporation, at94k40al Datasheet - Page 11

• Manufacturer Part Number: at94k40al
• Description: At94kal Series Field Programmable System Level Integrated Circuit
• Manufacturer: ATMEL Corporation

1138I–FPSLI–1/08
tions in horizontally aligned RAM blocks. For the left-most RAM blocks, RAddr is on the left and
WAddr is on the right. For the right-most RAM blocks, WAddr is on the left and RAddr is tied off.
For single-ported RAM, WAddr is the READ/WRITE address port and Din is the (bi-directional)
data port. The right-most RAM blocks can be used only for single-ported memories. WE and OE
connect to the vertical express buses in the same column on Plane V
WAddr, RAddr, WE and OE connect to express buses that are full length at array edge.
Reading and writing the 32 x 4 dual-port RAM are independent of each other. Reading the
32 x 4 dual-port RAM is completely asynchronous. Latches are transparent; when Load is logic
1, data flows through; when Load is logic 0, data is latched. Each bit in the 32 x 4 dual-port RAM
is also a transparent latch. The front-end latch and the memory latch together and form an edge-
triggered flip-flop. When a bit nibble is (Write) addressed and LOAD is logic 1 and WE is logic 0,
DATA flows through the bit. When a nibble is not (Write) addressed or LOAD is logic 0 or WE is
logic 1, DATA is latched in the nibble. The two CLOCK muxes are controlled together; they both
select CLOCK or they both select “1”. CLOCK is obtained from the clock for the sector-column
immediately to the left and immediately above the RAM block. Writing any value to the RAM
Clear Byte during configuration clears the RAM, see
Figure
Figure 2-6.
2-4.
FPGA RAM Connections (One RAM Block)
AT94KAL Series FPSLIC
Figure 2-3
and
CLK
CLK
CLK
CLK
CLK
WAddr
WE
OE
1
32X4 RAM
Din
Sector Clock Mux
and V
Dout
RAddr
2
, respectively.
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