SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
The random number generation data path begins in the analog block. The analog block contains a dedicated low drop-out regulator which supplies power to the entropy source, improving resistance to power manipulation attacks on the MCU supply. The sigma-delta entropy source itself derives entropy through delta-sigma modulation of Johnson-Nyquist noise.
During operation, the entropy source output is digitized and the digital output is sent to the digital conditioning block to generate a random bit stream. The conditioning block implements a stream cipher scheme. Following the conditioning block, a decimation block is provided to boost entropy by accumulating the entropy of a configurable number of samples. The output of the decimation block is finally captured in a result word holding register to be read by application software.