5.8.4. Timing annotation

TLM 2.0 supports the annotation of time to transactions. EVPs does honor such timing as described by the scenarios shown in Figure 5.15 and Figure 5.16.

Figure 5.15. Transaction issued by EVP

For Figure 5.15, the component in the EVP Core issues a read transaction to the SystemC component Memory. The transaction immediately returns annotating a delay of 10ns. The EVP ignores this annotation and continues the execution (read transaction #2) for the time quantum as if the memory had responded with a SC_ZERO_TIME delay.

Figure 5.16. Transaction issued by SystemC

For Figure 5.16, a transaction is issued by a component in the SystemC domain (Core) that accesses a memory modeled in the EVP (Memory). The timing annotation of the transaction is never be changed by the EVP because it runs in a temporal-decoupled way that assumes all transactions are handled immediately. Figure 5.16 shows two read transactions that are issued by a DMA component. The first transaction, marked with SC_ZERO_TIME, is answered by the memory component in the EVP immediately. Therefore the timing annotation is not changed. The second transaction is similar and the annotation of 10ns is also not changed by the memory component. This behavior is inherent to the temporal decoupled fast models and will not change for future releases.

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