BAT32G1x9 user manual | Chapter 32 Security features
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32.2 Registers used by the security function
The following registers are used for each function of the safety function.
Register name
The functions of the security function
• Flash CRC control register (CRC0CTL).
• Flash CRC Operation Result Register (PGCRCL).
Flash CRC operation function
(High Speed CRC).
• CRC Input Register (CRCIN).
• CRC Data Register (CRCD).
CRC arithmetic function
(Universal CRC).
•RAM Parity Error Control Register (RPECTL).
RAM parity error detection function
• Special SFR Protection Control Register (SFRGD).
SFR protection function
• Timer input selection register 0 (TIS0).
Frequency detection function
• A/D Test Register (ADTES).
A/D test function
•Port Mode Select Register (PMS).
Digital output signal level detection function on input/output
pins
The contents of each register are described in "32.3 Operation of
".
32.3 Operation of security features
32.3.1
Flash CRC operation function (high-speed CRC).
The IEC60730 standard requires confirmation of data in flash memory and recommends CRC as a
means of confirmation. This high-speed CRC checks the entire code flash area during the initial setup
(initialization) procedure.
The high-speed CRC stops the CPU and reads 32-bit data from flash through a clock for operation. As a
result, it is characterized by a shorter time to complete the inspection (e.g., 64KB flash memory:
512us@32MHz).
The CRC generates polynomials corresponding to CRC-16-CCITT's "X
16
+X
12
+X
5
+1".
MsBs of bit31
bit0 are prioritized.
Note Because the generic CRC
is
LSB
first, the results of the operation are different.
