NXP Semiconductors PXN2020, Reference Manual, Page: 340 / 1376

Flash Memory Array and Control
PXN20 Microcontroller Reference Manual, Rev. 1
12-14 Freescale Semiconductor
12.3.2.5 Low/Mid Address Space Block Select Register (LMS)
The Low/Mid Address Space Block Select Register (LMS) provides a means to select blocks to be
operated on during erase.
The LMS register is shown in Figure 12-7 and Table 12-8 .
Offset: FLASH_REG 0x000C Access: User read/write
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R SLE 0 0 0 0 0 0 0 0 0 0
SS
LOCK
0 0
SM
LOCK
W
Reset 0 0 0 0 0 0 0 0 0 0 0 1* 0 0 1* 1*
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R 0 0 0 0 0 0
SLLOCK
W
Reset 0 0 0 0 0 0 1* 1* 1* 1* 1* 1* 1* 1* 1* 1*
Figure 12-6. Secondary Low/Mid Address Block Locking Register (SLL)
Table 12-7. SLL Field Descriptions
Field Description
SLE Secondary Low/Mid Address Lock Enable. This bit is used to enable the Lock registers (SSLOCK,
SMLOCK, and SLLOCK) to be set or cleared by register writes. This bit is a status bit only, and may not
be written or cleared, and the reset value is 0. The method to set this bit is to provide a password, and
if the password matches, the SLE bit is set to reflect the status of enabled, and is enabled until a reset
operation occurs. For SLE, the password 0xC3C3_3333 must be written to the SLL register
0 Secondary Low/Mid Address Locks are disabled, and cannot be modified.
1 Secondary Low/Mid Address Locks are enabled to be written.
SSLOCK Secondary Shadow Lock. This bit is an alternative method that may be used to lock the shadow block
from programs and erases. SSLOCK has the same description as SLOCK. SSLOCK is not writable
unless SLE is high.
SMLOCK[1:0] Secondary Mid Address Block Lock. This bit is an alternative method that may be used to lock the Mid
Address Space blocks from programs and erases. SMLOCK has the same description as MLOCK.
SMLOCK is not writable unless SLE is high.
SLLOCK[9:0] Secondary Low Address Block Lock. This bit is an alternative method that may be used to lock the Low
Address Space blocks from programs and erases. SLLOCK has the same description as LLOCK.
SLLOCK is not writable unless SLE is high.