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https://github.com/openhwgroup/cvw
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Moved files around.
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163
pipelined/src/cache/AHBBuscachefsm.sv
vendored
163
pipelined/src/cache/AHBBuscachefsm.sv
vendored
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///////////////////////////////////////////
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// busfsm.sv
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//
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// Written: Ross Thompson ross1728@gmail.com December 29, 2021
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// Modified:
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//
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// Purpose: Load/Store Unit's interface to BUS for cacheless system
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//
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// A component of the Wally configurable RISC-V project.
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//
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// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
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//
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// MIT LICENSE
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// Permission is hereby granted, free of charge, to any person obtaining a copy of this
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// software and associated documentation files (the "Software"), to deal in the Software
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// without restriction, including without limitation the rights to use, copy, modify, merge,
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// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
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// to whom the Software is furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in all copies or
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// substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
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// OR OTHER DEALINGS IN THE SOFTWARE.
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////////////////////////////////////////////////////////////////////////////////////////////////
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`include "wally-config.vh"
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// HCLK and clk must be the same clock!
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module AHBBuscachefsm #(parameter integer WordCountThreshold,
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parameter integer LOGWPL, parameter logic CACHE_ENABLED )
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(input logic HCLK,
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input logic HRESETn,
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// IEU interface
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input logic [1:0] RW,
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input logic CPUBusy,
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output logic BusCommitted,
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output logic BusStall,
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output logic CaptureEn,
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// cache interface
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input logic [1:0] CacheRW,
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output logic CacheBusAck,
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// lsu interface
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output logic SelUncachedAdr,
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output logic [LOGWPL-1:0] WordCount, WordCountDelayed,
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output logic SelBusWord,
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// BUS interface
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input logic HREADY,
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output logic [1:0] HTRANS,
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output logic HWRITE,
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output logic [2:0] HBURST
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);
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typedef enum logic [2:0] {STATE_READY,
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STATE_CAPTURE,
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STATE_DELAY,
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STATE_CPU_BUSY,
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STATE_CACHE_FETCH,
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STATE_CACHE_EVICT} busstatetype;
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typedef enum logic [1:0] {AHB_IDLE = 2'b00, AHB_BUSY = 2'b01, AHB_NONSEQ = 2'b10, AHB_SEQ = 2'b11} ahbtranstype;
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(* mark_debug = "true" *) busstatetype BusCurrState, BusNextState;
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logic [LOGWPL-1:0] NextWordCount;
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logic FinalWordCount;
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logic [2:0] LocalBurstType;
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logic WordCntEn;
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logic WordCntReset;
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logic CacheAccess;
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always_ff @(posedge HCLK)
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if (~HRESETn) BusCurrState <= #1 STATE_READY;
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else BusCurrState <= #1 BusNextState;
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always_comb begin
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case(BusCurrState)
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STATE_READY: if(HREADY & |RW) BusNextState = STATE_CAPTURE;
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else if (HREADY & CacheRW[0]) BusNextState = STATE_CACHE_EVICT;
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else if (HREADY & CacheRW[1]) BusNextState = STATE_CACHE_FETCH;
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else BusNextState = STATE_READY;
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STATE_CAPTURE: if(HREADY) BusNextState = STATE_DELAY;
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else BusNextState = STATE_CAPTURE;
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STATE_DELAY: if(CPUBusy) BusNextState = STATE_CPU_BUSY;
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else BusNextState = STATE_READY;
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STATE_CPU_BUSY: if(CPUBusy) BusNextState = STATE_CPU_BUSY;
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else BusNextState = STATE_READY;
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STATE_CACHE_FETCH: if(HREADY & FinalWordCount) BusNextState = STATE_READY;
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else BusNextState = STATE_CACHE_FETCH;
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STATE_CACHE_EVICT: if(HREADY & FinalWordCount) BusNextState = STATE_READY;
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else BusNextState = STATE_CACHE_EVICT;
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default: BusNextState = STATE_READY;
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endcase
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end
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// IEU, LSU, and IFU controls
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flopenr #(LOGWPL)
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WordCountReg(.clk(HCLK),
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.reset(~HRESETn | WordCntReset),
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.en(WordCntEn),
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.d(NextWordCount),
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.q(WordCount));
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// Used to store data from data phase of AHB.
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flopenr #(LOGWPL)
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WordCountDelayedReg(.clk(HCLK),
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.reset(~HRESETn | WordCntReset),
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.en(WordCntEn),
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.d(WordCount),
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.q(WordCountDelayed));
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assign NextWordCount = WordCount + 1'b1;
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assign FinalWordCount = WordCountDelayed == WordCountThreshold[LOGWPL-1:0];
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assign WordCntEn = ((BusNextState == STATE_CACHE_EVICT | BusNextState == STATE_CACHE_FETCH) & HREADY) |
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(BusNextState == STATE_READY & |CacheRW & HREADY);
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assign WordCntReset = BusNextState == STATE_READY;
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assign CaptureEn = (BusCurrState == STATE_CAPTURE & RW[1]) | (BusCurrState == STATE_CACHE_FETCH & HREADY);
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assign CacheAccess = BusCurrState == STATE_CACHE_FETCH | BusCurrState == STATE_CACHE_EVICT;
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assign BusStall = (BusCurrState == STATE_READY & (|RW | |CacheRW)) |
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(BusCurrState == STATE_CAPTURE) |
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(BusCurrState == STATE_CACHE_FETCH) |
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(BusCurrState == STATE_CACHE_EVICT);
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assign BusCommitted = BusCurrState != STATE_READY;
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assign SelUncachedAdr = (BusCurrState == STATE_READY & |RW) |
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(BusCurrState == STATE_CAPTURE) |
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(BusCurrState == STATE_DELAY);
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// AHB bus interface
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assign HTRANS = (BusCurrState == STATE_READY & HREADY & (|RW | |CacheRW)) |
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(BusCurrState == STATE_CAPTURE & ~HREADY) |
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(CacheAccess & ~HREADY & ~|WordCount) ? AHB_NONSEQ :
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(CacheAccess & |WordCount) ? AHB_SEQ : AHB_IDLE;
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assign HWRITE = RW[0] | CacheRW[0];
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assign HBURST = (|CacheRW) ? LocalBurstType : 3'b0;
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always_comb begin
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case(WordCountThreshold)
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0: LocalBurstType = 3'b000;
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3: LocalBurstType = 3'b011; // INCR4
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7: LocalBurstType = 3'b101; // INCR8
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15: LocalBurstType = 3'b111; // INCR16
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default: LocalBurstType = 3'b001; // INCR without end.
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endcase
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end
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// communication to cache
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assign CacheBusAck = (CacheAccess & HREADY & FinalWordCount);
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assign SelBusWord = (BusCurrState == STATE_READY & (RW[0] | CacheRW[0])) |
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(BusCurrState == STATE_CAPTURE & RW[0]) |
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(BusCurrState == STATE_CACHE_EVICT);
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endmodule
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89
pipelined/src/cache/AHBCachedp.sv
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89
pipelined/src/cache/AHBCachedp.sv
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///////////////////////////////////////////
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// AHBCachedp.sv
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//
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// Written: Ross Thompson ross1728@gmail.com August 29, 2022
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// Modified:
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//
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// Purpose: Cache/Bus data path.
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// Bus Side logic
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// register the fetch data from the next level of memory.
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// This register should be necessary for timing. There is no register in the uncore or
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// ahblite controller between the memories and this cache.
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//
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// A component of the Wally configurable RISC-V project.
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//
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// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
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//
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// MIT LICENSE
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// Permission is hereby granted, free of charge, to any person obtaining a copy of this
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// software and associated documentation files (the "Software"), to deal in the Software
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// without restriction, including without limitation the rights to use, copy, modify, merge,
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// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
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// to whom the Software is furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in all copies or
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// substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
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// OR OTHER DEALINGS IN THE SOFTWARE.
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////////////////////////////////////////////////////////////////////////////////////////////////
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`include "wally-config.vh"
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module AHBCachedp #(parameter WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLED)
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(
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input logic HCLK, HRESETn,
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// bus interface
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input logic HREADY,
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input logic [`XLEN-1:0] HRDATA,
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output logic [2:0] HSIZE,
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output logic [2:0] HBURST,
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output logic [1:0] HTRANS,
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output logic HWRITE,
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output logic [`PA_BITS-1:0] HADDR,
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output logic [LOGWPL-1:0] WordCount,
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// cache interface
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input logic [`PA_BITS-1:0] CacheBusAdr,
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input logic [1:0] CacheRW,
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output logic CacheBusAck,
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output logic [LINELEN-1:0] FetchBuffer,
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output logic SelUncachedAdr,
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// lsu/ifu interface
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input logic [`PA_BITS-1:0] PAdr,
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input logic [1:0] RW,
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input logic CPUBusy,
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input logic [2:0] Funct3,
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output logic SelBusWord,
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output logic BusStall,
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output logic BusCommitted);
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localparam integer WordCountThreshold = CACHE_ENABLED ? WORDSPERLINE - 1 : 0;
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logic [`PA_BITS-1:0] LocalHADDR;
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logic [LOGWPL-1:0] WordCountDelayed;
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logic CaptureEn;
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genvar index;
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for (index = 0; index < WORDSPERLINE; index++) begin:fetchbuffer
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logic [WORDSPERLINE-1:0] CaptureWord;
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assign CaptureWord[index] = CaptureEn & (index == WordCountDelayed);
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flopen #(`XLEN) fb(.clk(HCLK), .en(CaptureWord[index]), .d(HRDATA),
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.q(FetchBuffer[(index+1)*`XLEN-1:index*`XLEN]));
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end
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mux2 #(`PA_BITS) localadrmux(CacheBusAdr, PAdr, SelUncachedAdr, LocalHADDR);
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assign HADDR = ({{`PA_BITS-LOGWPL{1'b0}}, WordCount} << $clog2(`XLEN/8)) + LocalHADDR;
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mux2 #(3) sizemux(.d0(`XLEN == 32 ? 3'b010 : 3'b011), .d1(Funct3), .s(SelUncachedAdr), .y(HSIZE));
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AHBBuscachefsm #(WordCountThreshold, LOGWPL, CACHE_ENABLED) AHBBuscachefsm(
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.HCLK, .HRESETn, .RW, .CPUBusy, .BusCommitted, .BusStall, .CaptureEn, .SelBusWord,
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.CacheRW, .CacheBusAck, .SelUncachedAdr, .WordCount, .WordCountDelayed,
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.HREADY, .HTRANS, .HWRITE, .HBURST);
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endmodule
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@ -1,141 +0,0 @@
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///////////////////////////////////////////
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// ahblite.sv
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//
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// Written: David_Harris@hmc.edu 9 January 2021
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// Modified:
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//
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// Purpose: AHB Lite External Bus Unit
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// See ARM_HIH0033A_AMBA_AHB-Lite_SPEC 1.0
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// Arbitrates requests from instruction and data streams
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// Connects core to peripherals and I/O pins on SOC
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// Bus width presently matches XLEN
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// Anticipate replacing this with an AXI bus interface to communicate with FPGA DRAM/Flash controllers
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//
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// A component of the Wally configurable RISC-V project.
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//
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// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
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//
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// MIT LICENSE
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// Permission is hereby granted, free of charge, to any person obtaining a copy of this
|
|
||||||
// software and associated documentation files (the "Software"), to deal in the Software
|
|
||||||
// without restriction, including without limitation the rights to use, copy, modify, merge,
|
|
||||||
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
|
|
||||||
// to whom the Software is furnished to do so, subject to the following conditions:
|
|
||||||
//
|
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||||||
// The above copyright notice and this permission notice shall be included in all copies or
|
|
||||||
// substantial portions of the Software.
|
|
||||||
//
|
|
||||||
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
|
|
||||||
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
|
|
||||||
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
|
||||||
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
|
||||||
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
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||||||
// OR OTHER DEALINGS IN THE SOFTWARE.
|
|
||||||
////////////////////////////////////////////////////////////////////////////////////////////////
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`include "wally-config.vh"
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module ahblite (
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input logic clk, reset,
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// Load control
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input logic UnsignedLoadM,
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input logic [1:0] AtomicMaskedM,
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// Signals from Instruction Cache
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input logic [`PA_BITS-1:0] IFUHADDR,
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input logic [2:0] IFUHBURST,
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input logic [1:0] IFUHTRANS,
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input logic IFUBusRead,
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input logic IFUTransComplete,
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logic IFUHWRITE,
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logic IFUHREADY,
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output logic IFUBusInit,
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output logic IFUBusAck,
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// Signals from Data Cache
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input logic [`PA_BITS-1:0] LSUHADDR,
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input logic [`XLEN-1:0] LSUHWDATA, // initially support AHBW = XLEN
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input logic [2:0] LSUHSIZE,
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input logic [2:0] LSUHBURST,
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input logic [1:0] LSUHTRANS,
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input logic LSUBusRead,
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input logic LSUBusWrite,
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input logic LSUTransComplete,
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logic LSUHWRITE,
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logic LSUHREADY,
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output logic LSUBusInit,
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output logic LSUBusAck,
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// AHB-Lite external signals
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(* mark_debug = "true" *) input logic HREADY, HRESP,
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(* mark_debug = "true" *) output logic HCLK, HRESETn,
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(* mark_debug = "true" *) output logic [`PA_BITS-1:0] HADDR, // *** one day switch to a different bus that supports the full physical address
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(* mark_debug = "true" *) output logic [`AHBW-1:0] HWDATA,
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output logic [`XLEN/8-1:0] HWSTRB,
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(* mark_debug = "true" *) output logic HWRITE,
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(* mark_debug = "true" *) output logic [2:0] HSIZE,
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(* mark_debug = "true" *) output logic [2:0] HBURST,
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(* mark_debug = "true" *) output logic [3:0] HPROT,
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(* mark_debug = "true" *) output logic [1:0] HTRANS,
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(* mark_debug = "true" *) output logic HMASTLOCK
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);
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localparam ADRBITS = $clog2(`XLEN/8); // address bits for Byte Mask generator
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typedef enum logic [1:0] {IDLE, MEMREAD, MEMWRITE, INSTRREAD} statetype;
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statetype BusState, NextBusState;
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||||||
logic LSUGrant;
|
|
||||||
logic [ADRBITS-1:0] HADDRD;
|
|
||||||
logic [1:0] HSIZED;
|
|
||||||
|
|
||||||
assign HCLK = clk;
|
|
||||||
assign HRESETn = ~reset;
|
|
||||||
|
|
||||||
// Bus State FSM
|
|
||||||
// Data accesses have priority over instructions. However, if a data access comes
|
|
||||||
// while an cache line read is occuring, the line read finishes before
|
|
||||||
// the data access can take place.
|
|
||||||
|
|
||||||
flopenl #(.TYPE(statetype)) busreg(HCLK, ~HRESETn, 1'b1, NextBusState, IDLE, BusState);
|
|
||||||
always_comb
|
|
||||||
case (BusState)
|
|
||||||
IDLE: if (LSUBusRead) NextBusState = MEMREAD; // Memory has priority over instructions
|
|
||||||
else if (LSUBusWrite) NextBusState = MEMWRITE;
|
|
||||||
else if (IFUBusRead) NextBusState = INSTRREAD;
|
|
||||||
else NextBusState = IDLE;
|
|
||||||
MEMREAD: if (LSUTransComplete & IFUBusRead) NextBusState = INSTRREAD;
|
|
||||||
else if (LSUTransComplete) NextBusState = IDLE;
|
|
||||||
else NextBusState = MEMREAD;
|
|
||||||
MEMWRITE: if (LSUTransComplete & IFUBusRead) NextBusState = INSTRREAD;
|
|
||||||
else if (LSUTransComplete) NextBusState = IDLE;
|
|
||||||
else NextBusState = MEMWRITE;
|
|
||||||
INSTRREAD: if (IFUTransComplete & LSUBusRead) NextBusState = MEMREAD;
|
|
||||||
else if (IFUTransComplete & LSUBusWrite) NextBusState = MEMWRITE;
|
|
||||||
else if (IFUTransComplete) NextBusState = IDLE;
|
|
||||||
else NextBusState = INSTRREAD;
|
|
||||||
default: NextBusState = IDLE;
|
|
||||||
endcase
|
|
||||||
|
|
||||||
// LSU/IFU mux: choose source of access
|
|
||||||
assign #1 LSUGrant = (NextBusState == MEMREAD) | (NextBusState == MEMWRITE);
|
|
||||||
assign HADDR = LSUGrant ? LSUHADDR : IFUHADDR;
|
|
||||||
assign HSIZE = LSUGrant ? {1'b0, LSUHSIZE[1:0]} : 3'b010; // Instruction reads are always 32 bits
|
|
||||||
assign HBURST = LSUGrant ? LSUHBURST : IFUHBURST; // If doing memory accesses, use LSUburst, else use Instruction burst.
|
|
||||||
assign HTRANS = LSUGrant ? LSUHTRANS : IFUHTRANS; // SEQ if not first read or write, NONSEQ if first read or write, IDLE otherwise
|
|
||||||
assign HPROT = 4'b0011; // not used; see Section 3.7
|
|
||||||
assign HMASTLOCK = 0; // no locking supported
|
|
||||||
assign HWRITE = (NextBusState == MEMWRITE);
|
|
||||||
|
|
||||||
// delay write data by one cycle for
|
|
||||||
flopen #(`XLEN) wdreg(HCLK, (LSUBusAck | LSUBusInit), LSUHWDATA, HWDATA); // delay HWDATA by 1 cycle per spec; *** assumes AHBW = XLEN
|
|
||||||
|
|
||||||
// Byte mask for HWSTRB based on delayed signals
|
|
||||||
flop #(ADRBITS) adrreg(HCLK, HADDR[ADRBITS-1:0], HADDRD);
|
|
||||||
flop #(2) sizereg(HCLK, HSIZE[1:0], HSIZED);
|
|
||||||
swbytemask swbytemask(.Size({1'b0, HSIZED}), .Adr(HADDRD), .ByteMask(HWSTRB));
|
|
||||||
|
|
||||||
// Send control back to IFU and LSU
|
|
||||||
assign IFUBusInit = (BusState != INSTRREAD) & (NextBusState == INSTRREAD);
|
|
||||||
assign LSUBusInit = (((BusState != MEMREAD) & (NextBusState == MEMREAD)) | (BusState != MEMWRITE) & (NextBusState == MEMWRITE));
|
|
||||||
assign IFUBusAck = HREADY & (BusState == INSTRREAD);
|
|
||||||
assign LSUBusAck = HREADY & ((BusState == MEMREAD) | (BusState == MEMWRITE));
|
|
||||||
endmodule
|
|
@ -1,86 +0,0 @@
|
|||||||
///////////////////////////////////////////
|
|
||||||
// busfsm.sv
|
|
||||||
//
|
|
||||||
// Written: Ross Thompson ross1728@gmail.com December 29, 2021
|
|
||||||
// Modified:
|
|
||||||
//
|
|
||||||
// Purpose: Load/Store Unit's interface to BUS for cacheless system
|
|
||||||
//
|
|
||||||
// A component of the Wally configurable RISC-V project.
|
|
||||||
//
|
|
||||||
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
|
|
||||||
//
|
|
||||||
// MIT LICENSE
|
|
||||||
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
|
|
||||||
// software and associated documentation files (the "Software"), to deal in the Software
|
|
||||||
// without restriction, including without limitation the rights to use, copy, modify, merge,
|
|
||||||
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
|
|
||||||
// to whom the Software is furnished to do so, subject to the following conditions:
|
|
||||||
//
|
|
||||||
// The above copyright notice and this permission notice shall be included in all copies or
|
|
||||||
// substantial portions of the Software.
|
|
||||||
//
|
|
||||||
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
|
|
||||||
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
|
|
||||||
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
|
||||||
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
|
||||||
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
|
|
||||||
// OR OTHER DEALINGS IN THE SOFTWARE.
|
|
||||||
////////////////////////////////////////////////////////////////////////////////////////////////
|
|
||||||
|
|
||||||
`include "wally-config.vh"
|
|
||||||
|
|
||||||
// HCLK and clk must be the same clock!
|
|
||||||
module AHBBusfsm
|
|
||||||
(input logic HCLK,
|
|
||||||
input logic HRESETn,
|
|
||||||
|
|
||||||
// IEU interface
|
|
||||||
input logic [1:0] RW,
|
|
||||||
input logic CPUBusy,
|
|
||||||
output logic BusCommitted,
|
|
||||||
output logic BusStall,
|
|
||||||
output logic CaptureEn,
|
|
||||||
input logic HREADY,
|
|
||||||
output logic [1:0] HTRANS,
|
|
||||||
output logic HWRITE
|
|
||||||
);
|
|
||||||
|
|
||||||
typedef enum logic [2:0] {STATE_READY,
|
|
||||||
STATE_CAPTURE,
|
|
||||||
STATE_DELAY,
|
|
||||||
STATE_CPU_BUSY} busstatetype;
|
|
||||||
|
|
||||||
typedef enum logic [1:0] {AHB_IDLE = 2'b00, AHB_BUSY = 2'b01, AHB_NONSEQ = 2'b10, AHB_SEQ = 2'b11} ahbtranstype;
|
|
||||||
|
|
||||||
(* mark_debug = "true" *) busstatetype BusCurrState, BusNextState;
|
|
||||||
|
|
||||||
always_ff @(posedge HCLK)
|
|
||||||
if (~HRESETn) BusCurrState <= #1 STATE_READY;
|
|
||||||
else BusCurrState <= #1 BusNextState;
|
|
||||||
|
|
||||||
always_comb begin
|
|
||||||
case(BusCurrState)
|
|
||||||
STATE_READY: if(HREADY & |RW) BusNextState = STATE_CAPTURE;
|
|
||||||
else BusNextState = STATE_READY;
|
|
||||||
STATE_CAPTURE: if(HREADY) BusNextState = STATE_DELAY;
|
|
||||||
else BusNextState = STATE_CAPTURE;
|
|
||||||
STATE_DELAY: if(CPUBusy) BusNextState = STATE_CPU_BUSY;
|
|
||||||
else BusNextState = STATE_READY;
|
|
||||||
STATE_CPU_BUSY: if(CPUBusy) BusNextState = STATE_CPU_BUSY;
|
|
||||||
else BusNextState = STATE_READY;
|
|
||||||
default: BusNextState = STATE_READY;
|
|
||||||
endcase
|
|
||||||
end
|
|
||||||
|
|
||||||
assign BusStall = (BusCurrState == STATE_READY & |RW) |
|
|
||||||
(BusCurrState == STATE_CAPTURE);
|
|
||||||
|
|
||||||
assign BusCommitted = BusCurrState != STATE_READY;
|
|
||||||
|
|
||||||
assign HTRANS = (BusCurrState == STATE_READY & HREADY & |RW) |
|
|
||||||
(BusCurrState == STATE_CAPTURE & ~HREADY) ? AHB_NONSEQ : AHB_IDLE;
|
|
||||||
assign HWRITE = (BusCurrState == STATE_READY) & RW[0]; // *** might not be necessary, maybe just RW[0]
|
|
||||||
assign CaptureEn = BusCurrState == STATE_CAPTURE;
|
|
||||||
|
|
||||||
endmodule
|
|
Loading…
Reference in New Issue
Block a user