Texas Instruments CC2650DK Benutzerhandbuch
Random Number Generator
16.7.1.6 CTL Register (Offset = 14h) [reset = X]
CTL is shown in
and described in
Control
Figure 16-9. CTL Register
31
30
29
28
27
26
25
24
STARTUP_CYCLES
R/W-X
23
22
21
20
19
18
17
16
STARTUP_CYCLES
R/W-X
15
14
13
12
11
10
9
8
RESERVED
TRNG_EN
RESERVED
R-X
R/W-X
R-X
7
6
5
4
3
2
1
0
RESERVED
NO_LFSR_FB
TEST_MODE
RESERVED
R-X
R/W-X
R/W-X
R/W-X
Table 16-11. CTL Register Field Descriptions
Bit
Field
Type
Reset
Description
31-16
STARTUP_CYCLES
R/W
X
This field determines the number of samples (between 2^8 and
2^24) taken to gather entropy from the FROs during startup. If the
written value of this field is zero, the number of samples is 2^24,
otherwise the number of samples equals the written value times 2^8.
0x0000: 2^24 samples 0x0001: 1*2^8 samples 0x0002: 2*2^8
samples 0x0003: 3*2^8 samples ... 0x8000: 32768*2^8 samples
0xC000: 49152*2^8 samples ... 0xFFFF: 65535*2^8 samples This
field can only be modified while TRNG_EN is 0. If 1 an update will
be ignored.
2^24) taken to gather entropy from the FROs during startup. If the
written value of this field is zero, the number of samples is 2^24,
otherwise the number of samples equals the written value times 2^8.
0x0000: 2^24 samples 0x0001: 1*2^8 samples 0x0002: 2*2^8
samples 0x0003: 3*2^8 samples ... 0x8000: 32768*2^8 samples
0xC000: 49152*2^8 samples ... 0xFFFF: 65535*2^8 samples This
field can only be modified while TRNG_EN is 0. If 1 an update will
be ignored.
15-11
RESERVED
R
X
Software should not rely on the value of a reserved. Writing any
other value than the reset value may result in undefined behavior.
other value than the reset value may result in undefined behavior.
10
TRNG_EN
R/W
X
0: Forces all TRNG logic back into the idle state immediately. 1:
Starts TRNG, gathering entropy from the FROs for the number of
samples determined by STARTUP_CYCLES.
Starts TRNG, gathering entropy from the FROs for the number of
samples determined by STARTUP_CYCLES.
9-3
RESERVED
R
X
Software should not rely on the value of a reserved. Writing any
other value than the reset value may result in undefined behavior.
other value than the reset value may result in undefined behavior.
2
NO_LFSR_FB
R/W
X
1: Remove XNOR feedback from the main LFSR, converting it into a
normal shift register for the XOR-ed outputs of the FROs (shifting
data in on the LSB side). A '1' also forces the LFSR to sample
continuously. This bit can only be set to '1' when TEST_MODE is
also set to '1' and should not be used for other than test purposes
normal shift register for the XOR-ed outputs of the FROs (shifting
data in on the LSB side). A '1' also forces the LFSR to sample
continuously. This bit can only be set to '1' when TEST_MODE is
also set to '1' and should not be used for other than test purposes
1
TEST_MODE
R/W
X
1: Enables access to the TESTCNT and LFSR0/LFSR1/LFSR2
registers (the latter are automatically cleared before enabling
access) and keeps IRQFLAGSTAT.NEED_CLOCK at '1'. This bit
shall not be used unless you need to change the LFSR seed prior to
creating a new random value. All other testing is done external to
register control.
registers (the latter are automatically cleared before enabling
access) and keeps IRQFLAGSTAT.NEED_CLOCK at '1'. This bit
shall not be used unless you need to change the LFSR seed prior to
creating a new random value. All other testing is done external to
register control.
0
RESERVED
R/W
X
Software should not rely on the value of a reserved. Writing any
other value than the reset value may result in undefined behavior.
other value than the reset value may result in undefined behavior.
1169
SWCU117A – February 2015 – Revised March 2015
Random Number Generator
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