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opencomputeproject / ODSA-BoW

Repo for all activity related to the ODSA Bunch of Wires Specification
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Add leverage existing PHYs as an objective #30

Open bapivee opened 4 years ago

bapivee commented 4 years ago

https://github.com/opencomputeproject/ODSA-BoW/blob/fcfbb6a3fc3d463f3ee4b81ce77c2b15393e2d49/spec/bow_specification/bow_specification.mdk#L133

Based on a discussion on 11/8/19. A proposal to add leveraging existing PHYs as an objective of the BoW specification.

bapivee commented 4 years ago

Proposal is to reuse one of LPDDR4, LPDDR5, HBM3. The aim is to reuse a lot of the circuitry and signaling. Existing PHY can be reused with some re-characterization. HBM 3 is one of the early IPs in any process nodes, choosing it as a target makes redesign by IP providers as quickly possible.

bapivee commented 4 years ago

Import HBM3 electrical. Bits per clock, bump pitches proposed, channel model. Analyze how difficult it is to design the I/Os, clocking and understand if it conflicts with other objectives. Else, we stay with current proposal. Ahmad Tavakoli to present in 3-4 weeks.

bapivee commented 4 years ago

Biggest decision - should we pair up with HBM3 low-swing definition or use rail-to-rail at a higher VDD.

rfarjad commented 4 years ago

"Leveraging an existing PHY" cannot be an objective, as it does not meet multiple objective guidelines, such as: • Objectives are problem statements, not solution statements --> It does not define a problem • Objectives set requirements to satisfy the target applications, to be met by the technical deliverables produced by the Task Force. --> It does not set a requirement • Objectives must be unambiguous --> It is surely ambiguous, as there are several "existing PHYs"