
9-51
Memory Usage Guide
Lattice Semiconductor
LatticeECP/EC and LatticeXP Devices
Figure 9-62. PFU Based ROM Timing Waveform – with Output Registers
Initializing Memory
In the EBR based ROM or RAM memory modes and the PFU based ROM memory mode, it is possible to specify
the power-on state of each bit in the memory array. Each bit in the memory array can have one of two values: 0 or
1.
Initialization File Format
The initialization file is an ASCII file, which a user can create or edit using any ASCII editor. IPexpress supports
three types of memory file formats:
1.
Binary file
2.
Hex File
3.
Addressed Hex
The file name for the memory initialization file is *.mem (<file_name>.mem). Each row depicts the value to be
stored in a particular memory location. The number of characters (or the number of columns) represents the num-
ber of bits for each address (or the width of the memory module).
The Initialization File is primarily used for configuring the ROMs. The EBR in RAM mode can optionally use this Ini-
tialization File also to preload the memory contents.
Add_0
Add_1
Add_2
Invalid Data
Data_0
OutClock
Address
Q
OutClockEn
t
SUADDR_PFU
t
HADDR_PFU
Data_1
Reset
t
CORAM_PFU