2-12
Architecture
Lattice Semiconductor LatticeECP/EC Family Data Sheet
Figure 2-14. DCS Waveforms
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-por t memory modes suppor t different widths on each of the por ts. 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 Mode Configurations
Single Port
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
256 x 36
True Dual Port
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
Pseudo Dual Port
8,192 x 1
4,096 x 2
2,048 x 4
1,024 x 9
512 x 18
256 x 36
CLK0
SEL
DCSOUT
CLK1
