From 2fd0d0d3efbad4fe60d327087d5c4275dff39aca Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Mon, 20 May 2019 04:56:09 +0100 Subject: [PATCH] add 6600 page --- 3d_gpu/6600scoreboard.mdwn | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/3d_gpu/6600scoreboard.mdwn b/3d_gpu/6600scoreboard.mdwn index 13d4851b1..96523f33f 100644 --- a/3d_gpu/6600scoreboard.mdwn +++ b/3d_gpu/6600scoreboard.mdwn @@ -2,5 +2,18 @@ # Modifications needed to Computation Unit and Group Picker +The scoreboard uses two big NOR gates respectively to determine when there +are no read/write hazards. These two NOR gates are permanently active +(per Function Unit) even if the Function Unit is idle. + +In the case of the Write path, these "permanently-on" signals are gated +by a Write-Release-Request signal that would otherwise leave the Priority +Picker permanently selecting one of the Function Units (the highest priority). +However the same thing has to be done for the read path, as well. + +Below are the modifications required to add a read-release path that +will prevent a Function Unit from requesting a GoRead signal when it +has no need to read registers. + [[!img comp_unit_req_rel.jpg]] [[!img group_pick_rd_rel.jpg]] -- 2.30.2