25.9.4 DMA CRC Polynomial A Register

Table 25-10. Register Bit Attribute Legend
Symbol	Description	Symbol	Description	Symbol	Description
R	Readable bit	HC	Cleared by Hardware	(Grey cell)	Unimplemented
W	Writable bit	HS	Set by Hardware	X	Bit is unknown at Reset
K	Write to clear	S	Software settable bit	—	—

Name:	CRCPOLYA
Offset:	0x0C
Reset:	0x00000000
Property:	PAC Write-Protection. Enable Write Protected


Bit	31	30	29	28	27	26	25	24
	POLYA[31:24]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	POLYA[23:16]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
	POLYA[15:8]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	POLYA[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bits 31:0 – POLYA[31:0] CRC Polynomial Coefficients Bits

The most significant polynomial term is always included in the CRC polynomial and is not required to be programmed in this register. This includes x32 for a 32-bit polynomial and x16 for a 16-bit polynomial.

For example, set this register to 0x741B8CD7 for the following 32-bit polynomial:

p(x) = x³² + x³⁰ + x²⁹ + x²⁸ + x²⁶ + x²⁰ + x¹⁹ + x¹⁷+ x¹⁶ + x¹⁵ + x¹¹ + x¹⁰ + x⁷ + x⁶+ x⁴ + x² + x + 1

Set this register to 0x00000589 for the following 16-bit polynomial p(x) = x¹⁶ + x¹⁰ + x⁸ + x⁷ + x³ + 1

Value	Description
0	Exclude xⁿfrom the CRC polynomial.
1	Include the term xⁿ, where n is the bit location, in the CRC polynomial.