7-34
MPC180E Security Processor User’s Manual
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Miscellaneous Routines
Figure 7-24. R
P
R
N
mod P Register Usage
Table 7-25. R
p
R
N
mod P
R
p
R
N
mod P
Computation
R
p
R
N
mod P, where R
p
= 2
16D
, and R
N
= 2
16E
; D is the number of digits of the modulus P,
and E is the number of digits of the modulus N, and D + 4 < E
Entry name
r2
Entry address
0x00c(r2)
Pre-conditions
Modsize = number of digits of the vector D - 1
EXP(k) SIZE = number of digits of the vector E-1
Post-conditions
B0-3 = R
p
R
N
mod P
N0-3 = modulus
Unless explicitly noted, all other registers are not guaranteed to be any particular value.
Special
conditions
—
N1
N2
N3
A0
A1
A2
A3
B0
B1
B2
B3
Initial Condition
Final Condition
N0
modulus P(
⇑
)
modulus P(
⇑
)
R
2
mod N(
⇑
)
RpRn
F2M
EXP(k)
regAsel
regBsel
regNsel
‘0’ - integer-modulo-n enabled
same
set (00)
Modsize
EXP(k)_SIZE
set (E-1)
set (D-1)
same
ECC
same
‘0’ - ECC disabled
same
‘1’ - RpRn enabled
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Freescale Semiconductor, Inc.
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m
ic
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to
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
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.
..