Texas Instruments OMAP36 Series, Technical Reference Manual

Page: 2010 / 3738

Public Version
L3 Interconnect
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9.2.3.3.4 REQ_INFO_PERMISSION Configuration
The firewall comparison mechanism enables access to a protected target only when a correct combination
of four MReqInfo in-band parameters is transmitted.
MReqInfo is a combination of a fixed 3-bit pattern that corresponds to a combination of the parameters
MReqDebug, MReqType, and MReqSupervisor.
Different valid MReqInfo combinations can be defined for each L3 firewall region based on the
L3_PM_REQ_INFO_PERMISSION_i value, which is programmed by software.
For each region, L3_PM_REQ_INFO_PERMISSION_i lists the possible MReqInfo combinations. Setting a
Reqbit in this register determines the type of access authorised to the initiator.
Table 9-22 lists the MReqInfo combinations available and the Reqbit associated with it.
Table 9-22. MReqInfo Parameter Combinations
Reqbit MReqInfo
MReqSupervisor MReqDebug MReqType
0 User Functional Data
1 User Functional Code
2 User Debug Data
3 User Debug Code
4 Reserved for non-GP devices
5 Reserved for non-GP devices
6 Reserved for non-GP devices
7 Reserved for non-GP devices
8 Supervisor Functional Data
9 Supervisor Functional Code
10 Supervisor Debug Data
11 Supervisor Debug Code
12 Reserved for non-GP devices
13 Reserved for non-GP devices
14 Reserved for non-GP devices
15 Reserved for non-GP devices
Figure 9-6 shows an example of the L3_PM_REQ_INFO_PERMISSION_i setting. In this example,
L3_PM_REQ_INFO_PERMISSION_i is set to 0x0C05 (16'b0000_1100_0001_0101) for a specific region,
which will grant access only if the request:
•
User + Func Data
• User + Debug + Data
• Supe Debug + Data
• Supe Debug + Code
2010 Interconnect SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated