4.5 Sequential instructions
Sequential instructions allow access to the target device in any combination of the small
instructions like erase, read, write sector, modify part of memory etc. Sequential instruction have an
access only when communication between target device and programming adapter is initialized. This
can be done when F_Open_Target_Device instruction is called. When communication is established,
then any of the sequential instruction can be called. When the process is finished, then at the end
F_Close_Target_Device instruction should be called. When communication is terminated, then
sequential instructions can not be executed.
Note: Erase/Write/Verify/Read configuration setup is not required when sequential instructions are
called. Also code file is not required to be downloaded. All data to be written, erased, and read is
specified as a parameter to the sequential functions. Data downloaded from the code file is ignored
in this case.
Very important:
The sequential functions allows to program words in the FLASH memory on any flash space location.
Also the same bytes / words can be programmed few times. Software is not be able to control how
many times the same location of the flash has been programmed between erasures. User should take
a full responsibility to program the flash memory according to the MSP430 specifications. See TI’s
data sheets and manuals for details.
The following flash programming limitation should be taken to consideration:
1. The same word or byte can not be programmed more then twice between erasures. Otherwise,
damage can occur.
2. In byte/word mode, the internally-generated programming voltage is applied to the complete
64-byte block, each time a byte or word is written, for 32 of the 35 f
FTG
cycles. With each byte
or word write, the amount of time the block is subjected to the programming voltage
accumulates. The cumulative programming time, t
CPT
, must not exceeded for any block. If the
cumulative programming time is met, the block must be erased before performing any further
writes to any address within the block. The cumulative time for the older MSP430
microcontrollers ( F1xx, F4xx) is typically 4 ms. For the newer ones - 10 ms. See the device-
specific datasheet for specifications. .
The FTG frequency used in the USB-MSP430-FPA with the single word (two bytes)
programming mode is 428 kHz. This means that programming time of the single word is appr
75 us. Programming time of the one byte would be the same.
Cumulative time for the 64 bytes uses byte write mode would be appr.
t
CPT
= 64(bytes) * 75 us = 4.8 ms.
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