82802AB Datasheet, PDF (27/53 Pages) Intel Corporation – Firmware Hub (FWH)

Intel^® 82802AB/AC Firmware Hub
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4.9.3.
4.9.3.1.
Random Number Generator Registers
When enabled and active, the Random Number Generator (RNG) is designed to fill an 8-bit register, a
bit at a time, with hardware-generated random numbers. When this register is full, a flag bit in the RNG
data status register transitions to a 1, indicating that a valid random number is ready to be read. This bit
will immediately reset to 0 upon reading the RNG data register.
The advantages of random numbers over pseudo-random numbers as well as a brief overview of the
simple mathematics of testing RNGs are discussed superficially in the companion document, The Intel^®
Platform RNG Tech Brief, which is available online.
RNG Hardware Status Register
Memory Address:
Default Value:
Access:
Size:
FFBC015Fh
40h, for typical component out of reset
RO
8 bits
4.9.3.2.
Bit
Function
7
Reserved
6
RNG Present—RO. Determines whether or not an RNG is present on this component, or if it has been
disabled.
1 = RNG Present
0 = RNG not present
5:1 Reserved
0
RNG Enabled—R/W. Determines whether the RNG is generating a random number.
1 = RNG enabled
0 = RNG disabled
RNG Data Status Register
Memory Address:
Default Value:
Access:
Size:
FFBC0160h
00h
RO
8 bits
Bit
Function
7:1 Reserved
0
RNG Output Valid. Determines whether the RNG data register contains a valid random number.
1 = RNG data register contians valid random data
0 = RNG data register contents not valid
Datasheet
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