Control FSM

nRF54LS05B Datasheet

The RNG is controlled by an finite state machine (FSM) which handles all the low-level interactions between the different hardware components described in Random number generator block diagram . During normal operation the FSM ensures that the entropy source is controlled in a NIST-800-90B compatible way, as shown in the following figure.

Figure 4. Control FSM state diagram

Page-1 Sheet.1 Reset Reset Sheet.2 Startup Startup Sheet.3 Fill FIFO Fill FIFO Sheet.4 FIFO full FIFO full Sheet.5 Error Error Dynamic connector Start (by software) Start(by software) Dynamic connector.7 Startup test success Startup testsuccess Dynamic connector.8 Health test failure Health test failure Dynamic connector.9 Health test failure Health test failure Dynamic connector.10 FIFO full FIFO full Dynamic connector.11 Health test failure Health test failure Dynamic connector.12 FIFO level low FIFOlevel low Dynamic connector.25 Soft reset (by software) Soft reset(by software)

The state diagram does not show that asserting the hard or soft resets and/or de-asserting the enable bit cause the state to be reset to "Reset".