Microcontroller User's Manual

8-16 MCF5282 User’s Manual MOTOROLA
System Access Control Unit (SACU)
8.6.3.1 Master Privilege Register (MPR)
The MPR specifies the access privilege level associated with each bus master in the
platform. The register provides one bit per bus master, where bit 3 corresponds to master 3
(Fast Ethernet Controller), bit 2 to master 2 (DMA Controller), bit1 to master 1 (internal
bus master), and bit 0 to master 0 (ColdFire core).
Only trusted bus masters can modify the access control registers. If a non-trusted bus master
attempts to write any of the SACU control registers, the access is aborted with an error
termination and the registers remain unaffected.
The processor core is connected to bus master 0 and is always treated as a trusted bus
master. Accordingly, MPR[0] is forced to 1 at reset.
8.6.3.2 Peripheral Access Control Registers (PACR 0–PACR8)
Access to several on-chip peripherals is controlled by shared peripheral access control
registers. A single PACR defines the access level for each of the two modules. These
0x028 PACR4 — PACR5 PACR6
0x02c PACR7 — PACR8 —
0x030 GPACR0 GPACR1 — —
0x034 — — — —
0x038 — — — —
0x03C — — — —
7 0
Field — MPR[3:0]
Reset 0000_0011
R/W R/W
Address IPSBAR + 0x020
Figure 8-8. Master Privilege Register (MPR)
Table 8-9. MPR[n] Field Descriptions
Bits Name Description
7–4 — Reserved. Should be cleared.
3–0 MPR Each 1-bit field defines the access privilege level of the given bus master n.
0 All bus master accesses are in user mode.
1 All bus master accesses use the sourced user/supervisor attribute.
Table 8-8. SACU Register Memory Map (continued)
IPSBAR
Offset
[31:28] [27:24] [23:20] [19:16] [15:12] [11:8] [7:4] [3:0]