Splitting a PROM File

You can retarget existing MCS, EXO, or TEK files to multiple serial or parallel PROM devices by splitting your PROM file into smaller files. Serial PROMs will be split into multiple serial PROMs, and byte wide PROMs will be split into multiple byte wide PROMs.

NOTE

You can only retarget MCS, TEK, and EXO file formats. You cannot retarget a HEX file because you cannot use this format to program a PROM device. Use HEX files for user-defined processes (for example, a microprocessor download) or programs.

The Split PROM Wizard retargets a PROM file to multiple PROM devices. The Split PROM Wizard always acts on the PROM file currently displayed in the PROM File Formatter.

To split a PROM file, use the following steps.

1. Activate the Split PROM Wizard in any of the following ways.
   
   
   • Select File Split PROM.
     
     If you are setting properties for a PROM file, specify Split PROM in the Format tab of the PROM Properties dialog box. A Split PROM Wizard button will appear in the dialog box; select the button.
     
     
   • If you try to save a PROM file into a PROM device that is too small, the Invalid PROM Size dialog box appears. Select the Split PROM option from this dialog box.
     
     The PROM File Formatter displays the Split PROM Wizard dialog box, shown in the following figure.
     
     

     Figure 3.8 Split PROM Wizard Dialog Box

2. Select one of the options displayed in the dialog box (Automatic, or Custom), then click the Next button. Depending on the option you select, proceed to one of the following sections to complete splitting the PROM file.
   
   
   • “Automatic Selection” section
     
     
   • “Custom Selection” section
     
     

Automatic Selection

The Automatic selection option of the Split PROM Wizard selects the minimum number of PROMs required to contain the data. If you selected Automatic in the Split PROM Wizard dialog box, the dialog box shown in the following figure appears.

Figure 3.9 Split PROM Wizard - Automatic

The information in this dialog box is read-only; it indicates the devices into which the PROM File Formatter divided the existing PROM file and the size of each device.

Select Finish to complete the PROM Wizard.

Custom Selection

The Custom selection option of the Split PROM Wizard allows you to select the PROMs into which you will target your data. If you selected Custom in the Split PROM Wizard dialog box, the dialog box shown in the following figure appears.

Figure 3.10 Split PROM Wizard - Custom

The three fields at the top of the dialog box provide information on the status of the current PROM file allocation.

• Bytes Required indicates the size of the PROM file you are splitting or total number of bytes to be allocated.
  
  
• Bytes Available indicates the number of bytes available in the set of devices you have chosen.
  
  
• Bytes Remaining indicates the number of bytes that still need to be allocated.
  
  

To build up the list of devices in the Devices Used list, perform the following operations.

• To add the first device to the Devices Used list, select the device in the Available Devices list and click >, or double-click the device in the Available Devices list.
  
  
• To add an additional device to the list, select the entry in the Devices Used list under which you want to enter the new device. Then perform either of the following:
  
  
  • In the Available Devices list, select the device you want to add and click >.
    
    OR
    
    
  • In the Available Devices list, double-click the device you want to add to the list.
    
    The selected PROM device appears in the Devices Used list, which displays the target PROMs in the order in which the PROM file is to be split.
    
    
• To change the order of the devices, select a device in the Devices Used list and click Move Up or Move Down.
  
  
• To delete a device from the list, select a device in the Devices Used list and click Remove.
  
  
• To empty the Devices Used list, click Remove All.
  
  

When you have finished building the Devices Used list, click the Finish button to split the PROM file using the devices you just specified in the listed order. The Finish button is grayed out and cannot be used until you have allocated all the bytes of your PROM file and the Bits Remaining box reaches 0.

When you click the Finish button, the PROM File Formatter creates a single PDR report file, multiple PRM files, and multiple PROM files as you specified in the Split PROM Wizard. The PDR report lists all the data streams and BIT files used to construct the PROM files as well as the load direction and PROM file splitting information. Each PRM file contains a memory map of the data for one PROM.

Each PROM file is assigned a default file name in the form of an appended 00, 01, ..., 0n suffix to the input file name. For example, if the original file name is design.mcs and the PROM file is split into three smaller PROM files, they will be named as follows: design00.mcs, design01.mcs, and design02.mcs.

The files are written to disk when you perform a Save or Save As command. The files are saved in the design directory.