Overlay Data

Overlay Data here refers to the concept of overlaying one set of data on top of another before programming. This enables the user to add dynamic data as part of the programming process. The overlay can be done programmatically using the Cyclone Control SDK, or on the command line using the Cyclone Control Console. Examples are provided for each below. The data itself can be in either hexadecimal format or string format; there are separate commands for each in both the Control SDK and the Control Console. 

When using an overlay function, the function passes the dynamic data that the user wants to program to a specific Cyclone handle (identifier). Prior to programming, that dynamic data will be overlaid on top of the static data in the user’s Programming Image. The user needs to provide:

• Which Cyclone should add the specified dynamic data (multiple cyclones may be launched)
• The memory address where the dynamic data will be written
• The dynamic data itself.

The Cyclone, as part of the launch process, will overlay the provided data on top of the static data in the Programming Image. Programming of the static and overlay data happens together so that devices which have ECC only have flash locations programmed a single time. Careful planning is required because it is possible for the Overlay Data to overlap areas already specified by the user in memory, and no error will be given. Almost always the user will leave gaps in the Image/Job Data to allow room for the Overlay Data.

Figure 1: User Provides Gaps in Object File (.s19/.bin/.elf/etc.) for Overlay Data

Below are examples for how the basic overlay commands are used in both the SDK and the Console. Please refer to the appropriate Cyclone User Manual for more granular information about overlay data command functions and parameters.

NOTE: One distinction of which to be aware between the SDK and Console is that when the SDK specifies overlay data for a specific Cyclone, that overlay data will continue to be used for each program launch until cleared by the clearOverlayProgramData(...) call, or until the connection to the Cyclone is closed. The Console, on the other hand, will always clear the overlay data upon exit of the application.

Cyclone Control SDK:

bool specifyOverlayProgramData(uint32_t cycloneHandle, uint32_t targetAddress, uint32_t dataLength, char* buffer);

The function has to be called prior to startImageExecution. The first parameter is the handle of the Cyclone. The second parameter is the address where the overlaying of the data starts. The third parameter is an array of bytes holding the data in hex.

data = [80,69,77,73,67,82,79]
specifyOverlayProgramData(1, 1080, data)     // Specify overlay data to be used when launching image
startImageExecution(1,1)   // Provide the overlay data to the Cyclone and Launch Programming
clearOverlayProgramData(1) // Clear overlay program data

Cyclone Control Console Example:

Here is the equivalent if the console is used to provide data at launch time: 

CycloneControlConsole.exe –cyclone=USB1 -specifyOverlayData=1,1080,80,69,77,73,67,82,79 -launchimage=1

Cyclone Control Suite and Licensing

The CycloneControlConsole and CycloneControlSDK Library are provided for free here.