FlexRay Module Registers
1340
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
FlexRay Module
26.3.2.1.7 Lock Register (LCK)
The lock register is write-only. Reading the register will return 00.
and
illustrate this register.
Figure 26-116. Lock Register (LCK) [offset_CC = 1Ch]
31
16
Reserved
R-0
15
8
7
0
TMK
CLK
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 26-95. Lock Register (LCK) Field Descriptions
Bit
Field
Value
Description
31-16
Reserved
0
Reads return 0. Writes have no effect.
15-8
TMK
0-1FFh
Test mode key. To write bit WRTEN in the test register to 1, the write operation has to be directly
preceded by two consecutive write accesses to the test mode key (unlock sequence). If this write
sequence is interrupted by other write accesses, bit WRTEN is not set to 1 and the sequence has
to be repeated.
First write (LCK.TMK): 75h = 0b0111 0101
Second write (LCK.TMK): 8Ah = 0b1000 1010
Third write: TEST1.WRTEN = 1
7-0
CLK
0-FFh
Configuration lock key. To leave CONFIG state by writing to CMD in the SUC configuration
register 1 (commands READY; MONITOR_MODE; ATM; LOOP_BACK), the write operation has to
be directly preceded by two consecutive write accesses to the configuration lock key (unlock
sequence). If this write sequence is interrupted by other write accesses, the communication
controller remains in CONFIG state and the sequence has to be repeated.
First write (LCK.CLK): CEh = 0b1100 1110
Second write (LCK.CLK): 31h = 0b0011 0001
Third write (SUCC.CMD)
NOTE:
In case that the Host uses 8/16-bit accesses to write the listed bit fields, the programmer has
to ensure that no "dummy accesses" (for example, the remaining register bytes / words) are
inserted by the compiler.