L-Bus to U-Bus Interface (L2U)
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
11-5
Figure 11-2. DMPU Basic Functional Diagram
11.5.1
Functional Description
Data memory protection is assigned on a regional basis. Default manipulation of the DMPU is done on a
global region. The DMPU has control registers that contain the following information: region protection
on/off, region base address, region size, and the region’s access permissions. Each region’s protection
attributes can be turned on or off by configuring the global region attribute register’s enable attribute bit
(L2U_GRA[ENRx]).
During each load or store access from the RCPU to the U-bus, the address is compared to the value in the
region base address register of each enabled region. Any access that matches the specific region within its
appropriate size, as defined by the region attribute register’s region size field (L2U_RAx[RS]), sets a
match indication.
When more than one match indication occurs, the effective region is the region with the highest priority.
Priority is determined by region number; highest priority corresponds to the lowest region number, e.g.
region 0 is highest priority, while region 3 is lowest.
When no match occurs, the effective region is the global region, which has the lowest priority.
The region attribute register also contains the region’s protection fields. The protection field (PP) of the
effective region is compared to the access attributes. If the attributes match, the access is permitted. When
the access is permitted, a U-bus access may be generated according to the specific attribute of the effective
region.
Region0 protection/attribute
Exception
Logic
Specific
Error Interrupts
to Core
Address
Access Attribute
Region1 protection/attribute
Region2 protection/attribute
Region3 protection/attribute
Global protection/attribute
Access
Region0 Address and size
Region1 Address and size
Region2 Address and size
Region3 Address and size
Granted
Match
Select
MSR[DR]
Region Protection/Attribute
Summary of Contents for MPC561
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Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
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Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...