If you want to update the bootloader with JTAG, use the .rom-files.
If you want to update with the bootloader itself, use .tft-files.
The 624 MHz bootloader will run on Trizeps-IV (WL) modules with 624 MHz speed-grade.
The 520 MHz bootloader will run on Trizeps-IV (WL) modules with 624 or 520 MHz speed-grade.
The 416 MHz bootloader will run on Trizeps-IV (WL) modules with 624,520 or 416 MHz speed-grade.
The 312 MHz bootloader will run on Trizeps-IV (WL) modules with 624,520,416 or 312 MHz speed-grade.
View the serial-number-sticker for speed-grade information.
Example:
16105.C520.R64.P32