SM320LF2407-EP Datasheet, PDF (30/112 Pages) Texas Instruments – 
DSP CONTROLLERS

SM320LF2407AĆEP
DSP CONTROLLERS
SGUS036B − JULY 2003 − REVISED OCTOBER 2003
flash/ROM security
240xA devices incorporate a security feature that prevents external access to program memory. This feature
is useful in preventing unauthorized duplication of proprietary code.
If access to Flash/ROM contents are desired for debugging purposes, two actions need to be taken:
1. A “dummy” read of locations 40h, 41h, 42h and 43h (of program memory space) is necessary. The word
“dummy” indicates that the destination address of this read is insignificant.
NOTE: Step 2 is not required if 40h−43h contain 0000 0000 0000 0000h or FFFF FFFF FFFF FFFFh.
2. A 64-bit password (split as four 16-bit words) must be written to the data-memory locations 77F0h, 77F1h,
77F2h, and 77F3h. The four 16-bit words written to these locations must match the four words stored in 40h,
41h, 42h, and 43h (of program memory space), respectively. The device becomes “unsecured” one cycle
after the last instruction that unsecures the part.
Code Security Module Disclaimer
The Code Security Module (“CSM”) included on this device was designed to password
protect the data stored in the associated memory (either ROM or Flash) and is warranted
by Texas Instruments (TI), in accordance with its standard terms and conditions, to
conform to TI’s published specifications for the warranty period applicable for this device.
TI DOES NOT, HOWEVER, WARRANT OR REPRESENT THAT THE CSM CANNOT BE
COMPROMISED OR BREACHED OR THAT THE DATA STORED IN THE
ASSOCIATED MEMORY CANNOT BE ACCESSED THROUGH OTHER MEANS.
MOREOVER, EXCEPT AS SET FORTH ABOVE, TI MAKES NO WARRANTIES OR
REPRESENTATIONS CONCERNING THE CSM OR OPERATION OF THIS DEVICE,
INCLUDING ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR
A PARTICULAR PURPOSE.
IN NO EVENT SHALL TI BE LIABLE FOR ANY CONSEQUENTIAL, SPECIAL,
INDIRECT, INCIDENTAL, OR PUNITIVE DAMAGES, HOWEVER CAUSED, ARISING
IN ANY WAY OUT OF YOUR USE OF THE CSM OR THIS DEVICE, WHETHER OR NOT
TI HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. EXCLUDED
DAMAGES INCLUDE, BUT ARE NOT LIMITED TO LOSS OF DATA, LOSS OF
GOODWILL, LOSS OF USE OR INTERRUPTION OF BUSINESS OR OTHER
ECONOMIC LOSS.
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