SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 817

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
The following formula is used to compute the deviation of the slave bit rate relative to the master
bit rate after synchronization (F
F
LIN Standard imposes that it must not exceed ±15%. The LIN Standard imposes also that for
communication between two nodes, their bit rate must not differ by more than ±2%. This means
that the Baudrate_deviation must not exceed ±1%.
It follows from that, a minimum value for the nominal clock frequency:
Examples:
TOL_UNSYNCH
• The Baud Rate
• The oversampling (Over=0 => 16X or Over=0 => 8X)
• Baudrate = 20 kbit/s, Over=0 (Oversampling 16X) => F
• Baudrate = 20 kbit/s, Over=1 (Oversampling 8X) => F
• Baudrate = 1 kbit/s, Over=0 (Oversampling 16X) => F
• Baudrate = 1 kbit/s, Over=1 (Oversampling 8X) => F
is the deviation of the real slave node clock from the nominal clock frequency. The
F
Baudrate_deviation
Baudrate_deviation
NOM
min
=
100
SLAVE
=
=
-------------------------------------------------------------------------------------------------- - Hz
is the real slave node clock frequency).
0.5
100
100
–
0.5
8
---------------------------------------------------------------------------------------------- - %
---------------------------------------------------------------------------------------------- - %
8
2 Over
+0.5
8
8
8
–
–
--------- -
100
15
F
-------------------------------------- - xF
2 Over
2 Over
+
TOL_UNSYNCH
Nom
-1
–
–
1
8
Nom
Nom
+
Nom
(min) = 74 kHz
100
1
(min) = 1.47 MHz
(min) = 132 kHz
F
(min) = 2.64 MHz
1%
SLAVE
+1
+
+
Baudrate
Baudrate
Baudrate
Nom
SAM3X/A
SAM3X/A
817
817