SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
The CLA can access three types of memory: program, data and message RAMs. The behavior and arbitration for each type of memory is described in this chapter. The CLA RAMs are protected by the DCSM module. Refer to the Dual Code Security Module (DCSM) section of the System Control and Interrupts chapter for more details on the security scheme.
The CLA program can be loaded with any of the local shared memories (LSxRAM). At reset, all memory blocks are mapped to the CPU. While mapped to the CPU space, the CPU can copy the CLA program code into the memory. During debug, the memory can also be loaded directly by the Code Composer Studio™ IDE.
Once the memory is initialized with CLA code, the CPU maps the memory to the CLA program space by:
When a memory block is configured as CLA program memory, debug accesses are allowed only on cycles where the CLA is not fetching a new instruction. A detailed explanation of the memory configurations and access arbitration (CPU, CLA, and DEBUG) process can be found in the Memory Controller Module section of the System Control and Interrupts chapter.
All CLA program fetches are performed as 32-bit read operations and all opcodes must be aligned to an even address. Since all CLA opcodes are 32-bits, this alignment occurs naturally.
Any of the device’s LSxRAMs can serve as data memory blocks to the CLA. At reset, all blocks are mapped to the CPU memory space, whereby the CPU can initialize the memory with data tables, coefficients, and so on, for the CLA to use.
Once the memory is initialized with CLA data, the CPU maps the memory to the CLA data space by:
When a memory block is configured as CLA data memory, CLA read and write accesses are arbitrated along with CPU accesses. The user has the option of turning on CPU fetch or write protection to the memory by writing to the appropriate bits of the MemCfgRegs.LSxACCPROTx registers. A detailed explanation of the memory configurations and access arbitration (CPU, CLA, and DEBUG) process can be found in the Memory Controller Module section of the System Control and Interrupts chapter.
There are two memory blocks for data sharing and communication between the CLA and the CPU . The message RAMs are always mapped to both CPU and CLA memory spaces, and only data access is allowed; no program fetches can be performed.