7.4 Commands – Detailed Description
7.4.1 General
7.4.2 RX Data Block
7.4.3 RX Password
Data Frame
See Table 1 .
Besides the header byte HDR (80h) and the command identification CMD, the frame length bytes L1 and
L2 (which must be equal) hold the number of bytes following L2, excluding the checksum bytes CKL and
CKH.
Bytes AL, AH, LL, LH, D1...Dn are command-specific. However, the checksum bytes CKL (low byte) and
CKH (high byte) are mandatory.
If the data frame has been received correctly and the command execution was successful, an
acknowledge character DATA_ACK = 90h is sent back by the BSL. Incorrectly received data frames,
unsuccessful operations, and commands that are locked or not defined are confirmed with a DATA_NAK =
A0h.
Note: BSL versions lower than V1.30 support only byte access operations. Therefore, the
peripheral module addresses at 0100h–01FFh cannot be accessed correctly, because
they are word-oriented. From version V1.30 and up, addresses 0000h–00FFh are
accessed in byte mode; all others are accessed in word mode.
The receive data block command is used for any write access to the flash memory/RAM or peripheral
module control registers at 0000h–01FFh. It is password protected.
The 16-bit even-numbered block start address is defined in AL (low byte) and AH (high byte). The 16-bit
even-numbered block length is defined in LL (low byte) and LH (high byte). Because pure data bytes are
limited to a maximum of 250, LH is always 0.
The following data bytes are succeeded by the checksum bytes CKL (low byte) and CKH (high byte). If
the receipt and programming of the appropriate data block was successful, an acknowledge character
DATA_ACK is sent back by the BSL. Otherwise, the BSL confirms with a DATA_NAK.
Note: BSL versions V1.40 and higher support online verification inside the MSP430 for
addresses 0200h–FFFFh, which reduces programming/verification time to 50%. Online
verification means that the data is immediately verified with the data that is written into the
flash without transmitting it again. In case of an error, the loadable bootstrap loader
BL_150S_14x.txt additionally stores the first incorrectly written location address+3 into the
error address buffer in the RAM at address 0200h (021Eh for F14x devices).
The receive password command is used to unlock the password-protected commands, which perform
reading, writing, or segment-erasing memory access. It is not password protected.
Neither start address nor block length information is necessary, because the 32-byte password is always
located at addresses FFE0h–FFFFh. Data bytes D1 to D20h hold the password information starting with
D1 at address FFE0h.
If the receipt and verification of the password is correct, a positive acknowledge DATA_ACK is sent back
by the BSL, and the password-protected commands become unlocked. Otherwise the BSL confirms with a
DATA_NAK.
Once the protected commands become unlocked, they remain unlocked until another BSL entry is
initiated.
SLAA089D – December 1999 – Revised August 2006 Features of the MSP430 Bootstrap Loader 7
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