RNG Execution Unit (RNG)
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 22-47

22.11.3 RNG Status Register (RNGSR)

This RNG status register, Figure 22-34, contains 4 bits which reflect the state of the RNG internal signals.

The RNG status register is read-only. Writing to this location will result in an address error being reflected

in the RNG interrupt status register.

Table 22-31 describes RNG status register fields.

Table 22-30. RNGRCR Field Descriptions

Bits Name Description
31-27 — Reserved
26 RI Reset Interrupt. Writing this bit active high causes RNG interrupts signalling DONE and
ERROR to be reset. It further resets the state of the RNG interrupt status register.
0 No reset
1 Reset interrupt logic
25 MI Module Initialization. This reset value performs enough of a reset to prepare the RNG for
another request, without forcing the internal control machines and the output FIFO to be
reset, thereby invalidating stored random numbers or requiring re-invocation of a warm-up
period. Module initialization is nearly the same as software reset, except that the interrupt
control register remains unchanged.
0 No reset
1 Reset most of RNG
24 SR Software reset is functionally equivalent to hardware reset (the RSTI pin), but only for the
RNG. All registers and internal states are returned to their defined reset state.
0 No reset
1 Full RNG reset
23-0 — Reserved
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R00HALT0OFRIE0RD00000000
W
Reset0000000000000000
1514131211109876543210
R0000000000000000
W
Reset0000000000000000
Reg
Addr
MBAR + 0x2E028

Figure 22-34. RNG Status Register (RNGSR)