Datasheet
MSP430x461x1, MSP430x461x
MIXED SIGNAL MICROCONTROLLER
19
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bootstrap loader (BSL)
The MSP430 BSL enables users to program the flash memory or RAM using a UART serial interface. Access
to the MSP430 memory via the BSL is protected by user-defined password. A bootstrap loader security key is
provided at address 0FFBEh to disable the BSL completely or to disable the erasure of the flash if an invalid
password is supplied. The BSL is optional for ROM-based devices. For complete description of the features of
the BSL and its implementation, see the application report Features of the MSP430 Bootstrap Loader, literature
number SLAA089.
BSLKEY DESCRIPTION
00000h Erasure of flash disabled if an invalid password is supplied
0AA55h BSL disabled
any other value BSL enabled
BSL FUNCTION PZ PACKAGE PINS
Data Transmit 87/A7 − P1.0
Data Receive 86/E7 − P1.1
flash memory
The flash memory can be programmed via the JTAG port, the bootstrap loader, or in system by the CPU. The
CPU can perform single-byte and single-word writes to the flash memory. Features of the flash memory include:
D Flash memory has n segments of main memory and two segments of information memory (A and B) of
128 bytes each. Each segment in main memory is 512 bytes in size.
D Segments 0 to n may be erased in one step, or each segment may be individually erased.
D Segments A and B can be erased individually, or as a group with segments 0 to n.
Segments A and B are also called information memory.
D New devices may have some bytes programmed in the information memory (needed for test during
manufacturing). The user should perform an erase of the information memory prior to the first use.