Freescale Semiconductor MPC5604B - Self Test Mode

MPC5604B/C Microcontroller Reference Manual, Rev. 8
Freescale Semiconductor 383
Figure 21-4. LINFlex in loop back mode
This mode is provided for self test functions. To be independent of external events, the LIN core ignores
the LINRX signal. In this mode, the LINFlex performs an internal feedback from its Tx output to its Rx
input. The actual value of the LINRX input pin is disregarded by the LINFlex. The transmitted messages
can be monitored on the LINTX pin.
21.6.2 Self Test mode
LINFlex can be put in Self Test mode by setting the LBKM and SFTM bits in the LINCR. This mode can
be used for a “Hot Self Test”, meaning the LINFlex can be tested as in Loop Back mode but without
affecting a running LIN system connected to the LINTX and LINRX pins. In this mode, the LINRX pin is
disconnected from the LINFlex and the LINTX pin is held recessive.
Figure 21-5. LINFlex in self test mode
21.7 Memory map and registers description
21.7.1 Memory map
See the “Memory map” chapter of this reference manual for the base addresses for the LINFlex modules.
Table 21-2 shows the LINFlex memory map.
LINTX LINRX
LINFlex
Tx
Rx
LINFlex
LINTX LINRX
Tx Rx
=1