Architecture
LatticeECP/EC Family Data Sheet
Lattice Semiconductor
Figure 2-14. DCS Waveforms
CLK0
CLK1
SEL
DCSOUT
sysMEM Memory
The LatticeECP/EC devices contain a number of sysMEM Embedded Block RAM (EBR). The EBR consists 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
Memory Mode
Configurations
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
256 x 36
Single Port
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
True Dual Port
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
256 x 36
Pseudo Dual Port
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.
2-12
LATTICE [ LATTICE SEMICONDUCTOR ]
