11.6.7 Tightly Coupled Memory
Users can use a part of the cache as Tightly Coupled Memory (TCM). The Cache Size Configuration determines the cache size by Software bits in the Cache Configuration register (CFG.CSIZESW). The relation between cache and TCM is as given below:
TCM size = (Maximum cache size - Configured cache size)
The user can obtain the TCM start address from the product memory mapping. The cache memory starts first from the address followed by the TCM memory. Size of the Way is fixed and the number of ways varies according to the available size for the cache memory. See Product Memory Mapping Overview from Related Links.
Maximum Cache | Configured Cache | TCM Size |
---|---|---|
4 KB | 4 KB | 0 KB |
4 KB | 2 KB | 2 KB |
4 KB | 1 KB | 3 KB |
4 KB | 0 KB | 4 KB |
The TCM is also accessible in its maximum size in case of disabling the CMCC. The TCM does not need to be locked to operate.