Freescale Semiconductor MK22FN256VDC12, Reference Manual

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32.3.3 RNGA Entropy Register (RNG_ER)
Specifies an entropy value that RNGA uses in addition to its ring oscillators to seed its
pseudorandom algorithm. This is a write-only register; reads return all zeros.
Address: 4002_9000h base + 8h offset = 4002_9008h
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
0
W
EXT_ENT
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
RNG_ER field descriptions
Field Description
31–0
EXT_ENT
External Entropy
Specifies an entropy value that RNGA uses in addition to its ring oscillators to seed its pseudorandom
algorithm.
NOTE: Specifying a value for this field is optional but recommended. You can write to this field at any
time during operation.
32.3.4 RNGA Output Register (RNG_OR)
Stores a random-data word generated by RNGA.
Address: 4002_9000h base + Ch offset = 4002_900Ch
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
RANDOUT
W
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
RNG_OR field descriptions
Field Description
31–0
RANDOUT
Random Output
Stores a random-data word generated by RNGA. This is a read-only field.
NOTE: Before reading RANDOUT, be sure it is valid (SR[OREG_LVL]=1).
Chapter 32 Random Number Generator Accelerator (RNGA)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
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