PXS20RM Datasheet, PDF (570/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Flash Memory
23.1.6.3 High Address Space Block Locking Register (HBL)
The High Address Space Block Locking Register (HBL) provides a means to protect blocks from being
modified.
NOTE
A reset value of 1* in Figure 23-5 indicates that the reset value of these
registers is determined by Flash values in the shadow block. An erased
shadow block causes the reset value to be 1.
Offset 0x0008
Access: User read/write
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
R _{HBE 0}
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
RESET: ₀
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R₀
0
0
0
0
0
0
0
0
0
HLOCK
W
RESET: ₀
0
0
0
0
0
0
0
0
0
1*
1*
1*
1*
1*
1*
= Unimplemented or Reserved
Figure 23-5. HBL Register
HBL register functions are shown in Table 23-6.
Table 23-6. HBL Field Descriptions
Field
Description
0
HBE
High Address Lock Enable This bit is used to enable the Lock registers (HLOCK) 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 HBE bit is set
to reflect the status of enabled, and is enabled until a reset operation occurs. For HBE, the password
B2B2_2222h must be written to the HBL register.
0 High Address Locks are disabled, and can not be modified
1 High Address Locks are enabled to be written
1-25
Reserved, reset to 0
26-31
HLOCK[5:0]
High Address Space Block Lock. HLOCK has the same characteristics as LLOCK. Please see this
description for more information. The block numbering for High Address Space starts with HLOCK[0]
and continues until all blocks are accounted.
HLOCK is not writable unless HBE is high.
23-20
PXS20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor