ST STM32F207 series - Figure 213. Bit, Byte and Half-Word Swapping

RM0033 Rev 9 553/1381
RM0033 Hash processor (HASH)
569
Figure 213. Bit, byte and half-word swapping
B y t e 3B y t e 2B y t e 1B y t e 0
bi
t s 7 . . . 0b i t s 7 .. . 0
b
i t s 7 .. . 0bi t s 7 . . . 0
H A S H_D I N
bit string organization in
bi t 0 bi t 1 bi t 2 9 b i t 3 0 b i t 3 1
Bit s w a p pi n g ope r a t i o n
b i t- s tr i n g g r o ws
i
n t hi s di rect io n
as
d e f i n e d b y
FIPS
PUB 1 80 - 2 s t d .
bi t 0bi t 1bi t 2bi t 3 0b i t 3 1
H A S H_D I N
B y t e s w a p ping ope r a t i o n
b i t- s tr i n g g r o ws
i
n t hi s di rect io n
as
d e f i n e d b y
FIPS
PUB 1 80 - 2 s t d .
B y t e 0B y t e 1B y t e 2B y t e 3
bi
t s 7 . . . 0b i t s 7 .. . 0
b
i t s 7 .. . 0bi t s 7 . . . 0
HA S H_ D I N
H a l f - w o r d s w a pping o p er a t io n
b i t-str in g g r o ws
i
n t h is d i rect i o n
a
s d e fi n e d b y
F
I PS PUB 18 0 - 2 s t d .
Half-wo r d 0
bi
t s 15 . . . 0
D A T A TYPE = bx 1 1
D
A T A T YPE = bx 10
D
A T A T YPE = bx 01
Half-wo r d 1
bi
t s 15 . . . 0
Half-wor d 0
bi
t s 15 .. . 0
Half-wor
d 1
bi
t s 15 .. . 0
“1” “0s”
p ad d ing is perfo r m ed
on this side of the
bit
s t ri n g.
ai16082b
Hash processor: Big-Endian
Bits entred with little-Endian format
A-In case of binary data hash, all bits should be swapped as below
B-In case of byte data hash, all bytes should be swapped as below
C-In case of half-word hash, all half-word should be swapped as below
Bytes entred with little-Endian format
Bit string organization in
Hash processor: Big-Endian
half word entred with little-Endian format
Bit string organization in
Hash processor: Big-Endian