8.6.5.17 AES Extended Mode Register

This register can only be written if the WPEN bit is cleared in the AES Write Protection Mode Register.

Name:	AES_EMR
Offset:	0xB0
Reset:	0x00000000
Property:	Read/Write


Bit	31	30	29	28	27	26	25	24
	BPE
Access	R/W
Reset	0


Bit	23	22	21	20	19	18	17	16
	NHEAD[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


Bit	15	14	13	12	11	10	9	8
	PADLEN[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


Bit	7	6	5	4	3	2	1	0
	PKRS	PKWL	PLIPD	PLIPEN		KSEL	APM	APEN
Access	R/W	R/W	R/W	R/W		R/W	R/W	R/W
Reset	0	0	0	0		0	0	0

Bit 31 – BPE Block Processing End

Value	Description
0	The AES_ISR.DATRDY flag reports only the end message encryption processing. No intermediate block processing is reported when SMOD=2. When a DMA is used to transfer data, BPE must be cleared.
1	The AES_ISR.DATRDY flag reports each end of block processing when SMOD=2. When AES_IDATARx are not loaded by a DMA and SMOD=2, this bit can be written to 1 to rise the AES_ISR.DATRDY flag when a new data block can be written.

Bits 23:16 – NHEAD[7:0] IPSec Next Header

Value	Description
0–255	IPSec Next Header field

Bits 15:8 – PADLEN[7:0] Auto Padding Length

Value	Description
0–255	Padding length in bytes

Bit 7 – PKRS Private Key Internal Register Select

Value	Description
0	The key used by the AES is in the AES_KEYWRx registers.
1	The key used by the AES is in the Private Key internal registers written through the Private Key bus.

Bit 6 – PKWL Private Key Write Lock

Once PKWL is set to ‘1’, only a hardware reset sets this bit to ‘0’ internally. Writing it to '0' with a register access has no impact (although the field will be read to value ‘0’).

Value	Description
0	The Private Key internal registers can be written multiple times via the Private Key bus.
1	The Private Key internal registers can be written only once via the Private Key bus until hardware reset.

Bit 5 – PLIPD Protocol Layer Improved Performance Decipher

Value	Description
0	Protocol layer improved performance is in Ciphering mode.
1	Protocol layer improved performance is in Deciphering mode.

Bit 4 – PLIPEN Protocol Layer Improved Performance Enable

Value	Description
0	Protocol layer improved performance is disabled.
1	Protocol layer improved performance is enabled.

Bit 2 – KSEL Key Selection for Encryption/Decryption

Value	Description
0	Selects the first key loaded by software.
1	Selects the second key loaded by software.

Bit 1 – APM Auto-Padding Mode

Value	Description
0	Auto-padding is performed according to the IPSec standard.
1	Auto-padding is performed according to the SSL standard.

Bit 0 – APEN Auto-Padding Enable

Value	Description
0	The Auto-padding feature is disabled.
1	The Auto-padding feature is enabled.