NXP Semiconductors MPC5602S, Справочное руководство

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Safety
MPC5606S Microcontroller Reference Manual, Rev. 7
118 Freescale Semiconductor
Figure 4-8. Change lock settings for mixed protection
The data written to SLBR n .SLB[0] is mirrored to SLBR n .SLB[1] as the corresponding register is 16-bit
protected. The data written to SLBR n .SLB[2] is blocked as the corresponding register is unprotected. The
data written to SLBR n .SLB[3] is written to SLBR n .SLB[3].
4.1.4.2.2 Enable locking via mirror module space (area #3)
It is possible to enable locking for a register after writing to it. To do so the mirrored module address space
must be used.
Figure 4-9 shows one example:
Figure 4-9. Enable locking via mirror module space (area #3)
When writing to address 0x0008 the registers MR9 and MR8 in the protected module are updated. The
corresponding lock bits remain unchanged (left part of
Figure 4-6 ).
When writing to address 0x2008 the registers MR9 and MR8 in the protected module are updated. The
corresponding lock bits SLBR2.SLB[1:0] are set while the lock bits SLBR2.SLB[3:2] remain unchanged
(right part of
Figure 4-6 ).
Figure 4-10 shows an example where some addresses are protected and some are not:
Figure 4-10. Enable locking for protected and unprotected addresses
SLB0 SLB1 0 SLB3
SLBR
update lock bits
1 SLBR n .WE[3:0]
to SLB0
write data
to SLB1 to SLB2 to SLB3
X X 1
SLBR 2
WE[3:0]
0 0 0 0 0 0 0 0
SLB[3:0]
16-bit write to address 0x0008
no change
write to
MR[9:8]
SLBR 2
WE[3:0]
0 0 0 0 1 1 0 0
SLB[3:0]
16-bit write to address 0x2008
set lock bits
write to
MR[9:8]
SLBR 3
WE[3:0]
0 0 0 0 0 0 0 0
SLB[3:0]
Before write access
SLBR 3
WE[3:0]
0 0 0 0 0 0 1 1
SLB[3:0]
32-bit write to address 0x200C
set lock bits
write to
MR[15:12]
After
write access