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