Motorola MCF5281, MCF5282 Grouped PeripheralAccess Control Register, Gpacr Field Descriptions

Models: MCF5282 MCF5281

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System Access Control Unit (SACU)

 

Table 8-13. Grouped PeripheralAccess Control Register

 

 

(GPACR) Field Descriptions

 

 

 

 

Bits

Name

Description

 

 

 

 

 

7

LOCK

This bit, once set, prevents subsequent writes to the GPACR. Any attempted write to the

 

 

 

GPACR generates an error termination and the contents of the register are not affected.

 

 

 

Only a system reset clears this flag.

 

 

 

 

 

6–4

Reserved, should be cleared.

 

 

 

 

 

3–0

ACCESS_CTRL

This 4-bit field defines the access control for the given memory region.

 

 

 

The encodings for this field are shown in Table 8-14.

 

 

 

 

 

At reset, these on-chip modules are configured to have only supervisor read/write access capabilities. Bit encodings for the ACCESS_CTRL field in the GPACR are shown in Table 8-14. Table 8-15shows the memory space protected by the GPACRs and the modules mapped to these spaces.

Table 8-14. GPACR ACCESS_CTRL Bit Encodings

Bits

Supervisor Mode

User Mode

 

 

 

0000

Read / Write

No Access

 

 

 

0001

Read

No Access

 

 

 

0010

Read

Read

 

 

 

0011

Read

No Access

 

 

 

0100

Read / Write

Read / Write

 

 

 

0101

Read / Write

Read

 

 

 

0110

Read / Write

Read / Write

 

 

 

0111

No Access

No Access

 

 

 

1000

Read / Write / Execute

No Access

 

 

 

1001

Read / Execute

No Access

 

 

 

1010

Read / Execute

Read / Execute

 

 

 

1011

Execute

No Access

 

 

 

1100

Read / Write / Execute

Read / Write / Execute

 

 

 

1101

Read / Write / Execute

Read / Execute

 

 

 

1110

Read / Write

Read

 

 

 

1111

Read / Write / Execute

Execute

 

 

 

MOTOROLA

Chapter 8. System Control Module (SCM)

8-19

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Motorola MCF5281 Grouped PeripheralAccess Control Register, Gpacr Field Descriptions, Gpacr Accessctrl Bit Encodings