LFEC10E-3F256C Lattice Semiconductor Corp., LFEC10E-3F256C Datasheet - Page 20

• Manufacturer Part Number: LFEC10E-3F256C
• Description: Latticeecp/ec Family of Fpga Devices Has Been Optimized to Deliver Mainstream Fpga Features at Low Cost.for Maximum Performance And Value, The Latticeecp (EConomy Plus) Fpga Concept Combines an Efficient Fpgafabric With High-speed Dedicated Functions
• Manufacturer: Lattice Semiconductor Corp.

Lattice Semiconductor
For more information on the PLL, please see details of additional technical documentation at the end of this data
sheet.
sysMEM Memory
The LatticeECP/EC family of devices contain a number of sysMEM Embedded Block RAM (EBR). The EBR con-
sists of a 9-Kbit RAM, with dedicated input and output registers.
sysMEM Memory Block
The sysMEM block can implement single port, dual port or pseudo dual port memories. Each block can be used in
a variety of depths and widths as shown in Table 2-6.
Table 2-6. sysMEM Block Configurations
Bus Size Matching
All of the multi-port memory modes support different widths on each of the ports. The RAM bits are mapped LSB
word 0 to MSB word 0, LSB word 1 to MSB word 1 and so on. Although the word size and number of words for
each port varies, this mapping scheme applies to each port.
RAM Initialization and ROM Operation
If desired, the contents of the RAM can be pre-loaded during device configuration. By preloading the RAM block
during the chip configuration cycle and disabling the write controls, the sysMEM block can also be utilized as a
ROM.
Memory Cascading
Larger and deeper blocks of RAMs can be created using EBR sysMEM Blocks. Typically, the Lattice design tools
cascade memory transparently, based on specific design inputs.
Single, Dual and Pseudo-Dual Port Modes
Figure 2-11 shows the four basic memory configurations and their input/output names. In all the sysMEM RAM
modes the input data and address for the ports are registered at the input of the memory array. The output data of
the memory is optionally registered at the output.
Single Port
True Dual Port
Pseudo Dual Port
Memory Mode
2-10
Configurations
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
256 x 36
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
256 x 36
512 x 18
LatticeECP/EC Family Data Sheet
Architecture