From ad6f12271f555e21306a1ad54cdaf26360d5ef49 Mon Sep 17 00:00:00 2001 From: lkcl Date: Thu, 27 Jun 2019 18:20:04 +0100 Subject: [PATCH] --- simple_v_extension/vblock_format.mdwn | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/simple_v_extension/vblock_format.mdwn b/simple_v_extension/vblock_format.mdwn index c535bdd4c..ed8fdd6c3 100644 --- a/simple_v_extension/vblock_format.mdwn +++ b/simple_v_extension/vblock_format.mdwn @@ -157,7 +157,16 @@ SUBVL and ssvoffs). # PCVBLK CSR Format -TBD +Using PCVBLK to store the progression of decoding of the VBLOCK allows a simple single issue design to only need to fetch 32 or 64 bits from the instruction cache on any given clock cycle. + +To support this option (where more complex implementations may skip some of these phases), VBLOCK contains partial decode state, that allows a trap to occur even oart-way through decode, in order to reduce latency. + +The format is as follows: + +| vlvalid | bvalid | vlset | 16xil | pplen | rplen | mode | vlblk | opptr | +| 1 | 1 | 1 | 3 | 2 | 2 | 1 | 16 | 5 | + + # Limitations on instructions -- 2.30.2