IM201

I want to add a clarification to this IM (IM201 -- Function arg data type
subset )

Specifically, about my request for 4-state (svLogicVecVal type) support in
SCEMI 2.0 brought up in the last face-to-face meeting.

What I had in mind was the ability to code up the software side (and the DPI
function formal arg types on the SV side), using the 4-state types
(svLogicVecVal on the C side, "reg" or "integer" on the SV side).

In pure simulation, users could run with full 4-state support. The IFLC
process, however, would map "X" and "Z" types into some TBD 2-state
representation (or, optionally, if an emulator implementation provided 4
state, no mapping would be required).

I don't think the end result is much different than that of the various
vendor implementations that exist currently for running SCEMI 1.1
testbenches in a pure simulation mode -- although there is no specification
for this (a weakness of SCEMI 1.1). Some of these implementations could pass
4-state info across the interface in pure simulation; some could do the
2-state mapping for both cases (simulation and emulation). The same issues
of possible simulation / emulation mismatch would continue if 4-state
semantics were defined in SCEMI 2.0. This is an opportunity to catalog and
define them, instead of just ignoring them.

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---    Russ Vreeland (949)926-6143  ---
---    vreeland@broadcom.com        ---
---    Senior Principal Engineer    ---
---    Broadcom Corporation         ---
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