On-Chip Flash Programming; Bitstream/Prom Sizes - Lattice Semiconductor MachXO2 Programming And Configuration Usage Manual

On-chip Flash Programming

As shown in Table 1, on-chip Flash is programmed with different programming modes. These programming modes
are discussed in the next sections. Within the different programming modes, there are two methods of program-
ming the on-chip Flash: Offline and Background programming.
Offline Programming - This method requires the device to enter into programming mode. When in programming
mode, the device stops working, until the programming is completed. When using Diamond Programmer, the
Offline Mode is selected using operations starting with FLASH. Unless noted by the operation, the Flash sectors
accessed are Feature, Configuration and UFM.
Background Programming - This method allows the device to continue operating in User Mode, while the config-
uration logic programs the on-chip Flash memory. When the on-chip Flash memory programming is completed, the
device can download into the SRAM with REFRESH instruction. When using Diamond Programmer, the Back-
ground Mode is selected using operations starting with XFLASH. Unless noted by the operation, the Flash sectors
accessed are Configuration and UFM.
Note that if background programming is used on the MachXO2-2000U, MachXO2-4000 and MachXO2-7000, the
system must put the right side PLL in reset state during background programming. The required duration, erase
portion, of the background Flash programming time is specified in Table 97 of TN1246,
and Hardened Control Functions in MachXO2 Devices Reference
background programming.

Bitstream/PROM Sizes

The MachXO2 is a SRAM based FPGA. The SRAM configuration memory must be loaded from a non-volatile
memory that can store all of the configuration data. The size of the configuration data is variable. It is based on the
amount of logic available in the FPGA, and the number of pre-initialized Embedded Block RAM (EBR) components.
A MachXO2 design using the largest device, with every EBR pre-initialized with unique data values, and generated
without compression turned on requires the largest amount of storage.
Storing configuration data in the MachXO2's internal Flash memory has special considerations. The Flash memory
in the MachXO2 provides three independent sectors. The first sector is dedicated for use in holding compressed
configuration data, and is called Configuration Flash. The second sector, called the User Flash Memory, provides
three different functions. It provides additional Configuration Flash storage for large configuration data images, it
can store EBR contents, or it is available for use as general purpose Flash memory. The third sector is the Feature
Row.
Figure 3. Flash Memory Space of a MachXO2 Device
MachXO2 Programming and Configuration Usage Guide
Row Size = M Configuration Flash
Row Size = N
7
Guide. The left side PLL can stay active during
128 Bits
Usercode
UFM
Feature Row
Using User Flash Memory