System Control Memory Registers
595
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Internal Memory
7.5.4 FMPRE0 to FMPRE15 Registers (Offset = 0x200 to 0x23C) [reset = 0xFFFFFFFF]
Flash Memory Protection Read Enable 0 (FMPRE0), offset 0x200
Flash Memory Protection Read Enable 1 (FMPRE1), offset 0x204
Flash Memory Protection Read Enable 2 (FMPRE2), offset 0x208
Flash Memory Protection Read Enable 3 (FMPRE3), offset 0x20C
Flash Memory Protection Read Enable 4 (FMPRE4), offset 0x210
Flash Memory Protection Read Enable 5 (FMPRE5), offset 0x214
Flash Memory Protection Read Enable 6 (FMPRE6), offset 0x218
Flash Memory Protection Read Enable 7 (FMPRE7), offset 0x21C
Flash Memory Protection Read Enable 8 (FMPRE8), offset 0x220
Flash Memory Protection Read Enable 9 (FMPRE9), offset 0x224
Flash Memory Protection Read Enable 10 (FMPRE10), offset 0x228
Flash Memory Protection Read Enable 11 (FMPRE11), offset 0x22C
Flash Memory Protection Read Enable 12 (FMPRE12), offset 0x230
Flash Memory Protection Read Enable 13 (FMPRE13), offset 0x234
Flash Memory Protection Read Enable 14 (FMPRE14), offset 0x238
Flash Memory Protection Read Enable 15 (FMPRE15), offset 0x23C
This register stores the read-only protection bits for each 2KB flash block (FMPPEn stores the execute-
only bits). Note that for protecting sectors, eight bits need to be cleared to create a 16KB read-protected
sector.
This register is loaded during the power-on reset sequence. The factory settings for the FMPREn and
FMPPEn registers are a value of 1 for all implemented banks. This achieves a policy of open access and
programmability. The register bits may be changed by writing the specific register bit. However, this
register is RW0; the user can only change the protection bit from a 1 to a 0 (and may NOT change a 0 to
a 1). The changes are not permanent until the register is committed (saved), at which point the bit change
is permanent. If a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a
power-on reset sequence. The reset value shown only applies to power-on reset; any other type of reset
does not affect this register. Once committed, the only way to restore the factory default value of this
register is to perform the "Recover Locked Device" sequence detailed in the JTAG chapter.
NOTE:
Do not clear bits [7:0] of the FMPRE0 register to read protect the first 16KB of the flash
memory. If this part of memory is read protected, the device cannot boot up, because the
ROM reads address 0x4 to determine if a valid application resides in flash memory.
Each FMPREn register controls a 64K block. For additional information, see
•
FMPRE0 : 0 to 64KB
•
FMPRE1 : 65 to 128KB
•
FMPRE2 : 129 to 192KB
•
FMPRE3 : 193 to 256KB
•
FMPRE4 : 257 to 320KB
•
FMPRE5 : 321 to 384KB
•
FMPRE6 : 385 to 448KB
•
FMPRE7 : 449 to 512KB
•
FMPRE8 : 513 to 576KB
•
FMPRE9 : 577 to 640KB
•
FMPRE10 : 641 to 704KB