PXS20RM Datasheet, PDF (1050/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

LIN Controller (LINFlexD)
Example 31-1.
If LINIBRR = 27d and LINFBRR = 12d, then
Mantissa (LFDIV) = 27d
Fraction (LFDIV) = 12/16 = 0.75d
Therefore LFDIV = 27.75d
Example 31-2.
To program LFDIV = 25.62d,
LINFBRR = 16 * 0.62 = 9.92, nearest real number 10d = Ah
LINIBRR = mantissa(25.620d) = 25d = 19h
NOTE
The Baud Counters are updated with the new value of the Baud Registers
after a write to LINIBRR. Hence the Baud Register value must not be
changed during a transaction. The LINFBRR (containing the Fraction bits)
must be programmed before LINIBRR.
NOTE
LFDIV must be greater than or equal to 1.5d, for example, LINIBRR = 1
and LINFBRR = 8. Therefore, the maximum possible baudrate is
fperiph_set_1_clk / 24.
Table 31-51. Error calculation for programmed baud rates
f_{ipg_clock_lin} = MHz
f_{ipg_clock_lin} = 16 MHz
Baud rate
Actual
Value programmed in % Error =
the baud rate register (Calculated -
Desired)
Baud rate
LINIBRR LINFBRR / Desired
baud rate
Actual
Value programmed in % Error =
the baud rate register (Calculated -
Desired)
Baud rate
LINIBRR LINFBRR / Desired
baud rate
10417 10416.7
383
16
-0.003
10416.7
95
16
-0.003
31.13 Programming considerations
This section describes the various configurations in which the LINFlexD can be used.
31-74
PXS20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor