7.4.4 Mass Erase
7.4.5 Erase Segment
Data Frame
The mass erase command erases the entire flash memory area (main memory plus information memory,
see corresponding data sheet). It is not password protected.
All parameters shown in Table 1 are mandatory. After erasing, an acknowledge character DATA_ACK is
sent back by the BSL.
Mass erase initializes the password area to 32 times 0FFh.
Note: BSL versions V2.01 and higher support automatic clearing of the LOCKA bit protecting
information flash memory. When the BSL is entered from a rest condition, LOCKA is
cleared by the BSL in order to mass erase the flash, including information memory. When
the BSL is entered in-application, user software should take care that LOCKA = 1 prior to
initiating the BSL. Otherwise, information flash will not be erased during a BSL mass
erase.
The erase segment command erases specific flash memory segments. It is password protected.
The address bytes AL (low byte) and AH (high byte) select the appropriate segment. Any even-numbered
address within the segment to be erased is valid. After segment erasing, an acknowledge character
DATA_ACK is sent back by the BSL (V1.40 or lower).
BSL versions V1.60 or higher perform a subsequent erase check of the corresponding segment and
respond with a DATA_NAK if the erasure was not successful. In this case, the first unerased location
address + 1 is stored in the error address buffer in the RAM at address 0200h (021Eh for F14x devices).
In this version, a problem occurs if only one of the information memory segments is erased. In this case,
an error is reported, because an automatic erase check over the whole information memory is performed.
As a solution, either erase the whole information memory or do a separate erase check after the erase,
even if the erase reported an error.
Erase segment 0 clears the password area and, therefore, the remaining password is 32 times 0FFh.
When applying LL = 0x04 and LH = 0xA5, a mass erasure of only the main memory is performed. Indeed,
this command must be executed a minimum of 12 times to achieve a total erasure time of >200 ms. No
subsequent erase check of the entire main memory is done. Use the erase check command additionally.
Check the device datasheet for more information on the cumulative (mass) erase time that must be met
and the number of erase cycles required.
8 Features of the MSP430 Bootstrap Loader SLAA089D – December 1999 – Revised August 2006
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