Circuit Board Reference Manual

Descriptors
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 22-57
Figure 22-40. Data Packet Descriptor Format
22.13.1.1 Descriptor Header
Descriptors are created by the host to guide the SEC through required crypto-graphic operations. The
descriptor header defines the operations to be performed, mode for each operation, and internal addressing
used by the controller and channel for internal data movement. Figure 22-41 shows the descriptor header.
.
Table 22-38 defines the header bits.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Field PEUSEL PMODE SEUSEL
1514131211109876543210
Field SMODE TYPE — ST DN
Addr Descriptor Pointer + 0x0
Figure 22-41. Descriptor Header
Descriptor Header
Data Field Length 1
Data Field Pointer 1
Data Field Length 2
Data Field Pointer 2
Data Field Length 3
Data Field Pointer 3
Data Field Length 4
Data Field Pointer 4
Data Field Length 5
Data Field Pointer 5
Data Field Length 6
Data Field Pointer 6
Data Field Length 7
Data Field Pointer 7
Next Descriptor Pointer
Descriptor Pointer
+0x04
+0x20
+0x24
+0x28
+0x2C
+0x30
+0x34
+0x38
+0x0C
+0x08
+0x18
+0x1C
+0x14
+0x10
+0x3C