General ESL Interactions with Shortcuts Illustrated

Consider the »Ethernet CRC example

Another useful taxonomy over the higher modelling abstractions:

1. Highest-level (vanished) model: Implemented using SystemC or another threads package: device driver code and device model mostly missing, but the API to the device driver is preserved, for instance, a single TLM transaction might send a complete packet when in reality multiple bus cycles are needed to transfer such a packet;
2. Mid-level model: Implemented using SystemC: the device driver is only slightly modified (using preprocessor directives or otherwise) but the interconnection between the device and its driver may be different from reality, meaning bus utilisation figures are unobtainable or incorrect;
3. Bus-transaction accurate mode: each bus operation (read/write or burst read/write and interrupt) is modelled, so bus loading can be established, but timing may be loose and transaction order may be wrong, again, minor changes in the device driver and native compilation may be used;
4. Low-level model: Implemented in RTL or cycle-accurate SystemC: target device driver firmware and other code is used unmodifed.