Using C to Access Data Stored in Program Space Memory on the TMS320C24x DSP

Efficient utilization of available memory in a TMS320C24x? DSP sometimes requires the placement of data in program space memory (as opposed to data space memory). In particular, the on-chip flash (or ROM) in the program space provides a large nonvolatile memory for storing constant arrays, look-up tables, and string tables. However, accessing this data using the C programming language is problematic, since the C-compiler provides no mechanism for accessing program space. This application note presents a C-callable library of six assembly code functions for accessing data in program space memory. These functions work with all members of the C24x? DSP generation, including all C/F24x, LC/LF240x, and LC/LF240xA devices.

Note: These functions cannot be used to program the on-chip flash memory. Programming the flash requires using one of several different flash programming utilities. These utilities are available on the Texas Instruments (TI) website, www.ti.com.