STAPL file
STAPL, which stands for Standard Test and Programming Language, is a file format and scripting language used for programming and testing devices over JTAG (Joint Test Action Group) interfaces. Originally developed by the JEDEC organization (Joint Electron Device Engineering Council), STAPL files — commonly using the .jam extension - are most often associated with programmable logic devices (PLDs), such as FPGAs, CPLDs, and configuration PROMs.
File Format
A STAPL file contains both data (e.g., configuration bitstreams) and executable scripts written in a high-level interpreted language called JAM/STAPL. These scripts instruct the programmer how to interface with the target device over JTAG and handle operations such as:
- Device detection
- Erasing and programming
- Verifying configuration
- Reading device IDs or statuses
This scripting capability makes STAPL flexible and vendor-independent, allowing programming instructions to be embedded within the file itself.
Common Use Cases
STAPL files are used for:
- Programming CPLDs and FPGAs from vendors like Lattice Semiconductor or Intel/Altera.
- Configuring devices using boundary scan techniques.
- Updating firmware in-field without requiring proprietary programmer software.