Initial commit of OpenSPARC T2 design and verification files.

[OpenSPARC-T2-DV] / verif / model / vendor / TLM-2006-11-29 / tlm / tlm_bus / README.txt

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The basic rules for all the interfaces in the TLM 2.0 kit are effective pass by\r
value.Effective pass-by-value is used to implement message passing semantics.\r
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However, an exception is made for the pointer versions of tlm_request and\r
tlm_response. These use pass by pointer for the data and byte enable fields.\r
However, the basic message passing semantics will be preserved by obeying the\r
rules below.\r
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1. Allocate and Deallocation\r
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1.1 If a process deallocates the arrays, the same process must deallocate the\r
arrays.\r
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1.2 If you can't or won't deallocate, use pass-by-val\r
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1.3 People may call you a master, system initiator or whatever if you allocate\r
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2 Read / Write Permissions\r
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2.1 If you're a master and the transaction is a write, you have write\r
permission on the arrays in the request\r
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2.2 If you're a master and the transaction is a read, you have read permission\r
on the arrays in the response\r
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2.3 If you're a slave and the transaction is a write, you have read permission\r
on the data in the request\r
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2.4 If you're a slave and the transaction is a read, you have write permission\r
on the data in the response\r
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2.5 No other read or write permissions are granted on the arrays other than\r
those specified above. \r
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3 Request / Response matching\r
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3.1 The slave must copy the pointers to the arrays from request to response.\r
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3.2 The arrival of the response back at the master is used to determine when\r
to deallocate or reuse the arrays.\r
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4 Analysis\r
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4.1 If you're doing analysis you must use the analysis interface ( eg\r
monitoring, functional coverage, performance analysis, scoreboarding )\r
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4.2 If you're designing a life extending analysis component ( eg a scoreboard )\r
then you must use analysis_fifo or analysis_buffer with the by-val variants of\r
the request and response datastructures.\r
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4.3 If you're connecting a by-pointer TLM to a life extending analysis\r
component, you must convert from by-pointer to by-val.\r
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