Cmsemicon CMS32L051 - 24.2 Registers used by security functions; 24.3 Operation of security functions

V1.2.2
CMS32L051 User Manual |Chapter 24 Security Features
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24.2 Registers used by security functions
Each function of the safety function uses the following registers.
Register name
Functions of the security function
 CRC Control Register (CRC0CTL).
 CRC Result Register (PGCRCL).
Flash CRC operation function
(High Speed CRC).
).

CRC operation function
(General CRC).

RAM parity error detection function

SFR protection function
 0 (TIS0).
Frequency detection function

A/D test function
).
Digital output signal level detection function at the
input/output pin
The contents of each register are described in 24.3 Operation of security functions.
24.3 Operation of security functions
24.3.1 Flash CRC operation function (high-speed CRC)
The IEC60730 standard requires the confirmation of data in flash memory and recommends CRC as a
means of confirmation. This high-speed CRC inspects the entire code flash memory area during the
initialization (initialization) program.
The high-speed CRC stops the operation of the CPU and reads 32-bit data from the flash memory
through 1 clock for operation. Therefore, it is characterized by a shorter time to complete the check (e.g.,
64KB of flash: 512us@32MHz).
CRC generates a polynomial corresponding to CRC-16-CCITT's X
16
+X
12
+X
5
+1.
Operate on the MSB of bit31→bit0 first.
Note Because the generic CRC is LSB first, the results are different.