cvw/src/ebu/controllerinput.sv
2024-10-15 10:27:53 -05:00

87 lines
4.2 KiB
Systemverilog

///////////////////////////////////////////
// controllerinput.sv
//
// Written: Rose Thompson rose@rosethompson.net
// Created: August 31, 2022
// Modified: 18 January 2023
//
// Purpose: AHB multi controller interface to merge LSU and IFU controls.
// See ARM_HIH0033A_AMBA_AHB-Lite_SPEC 1.0
// Arbitrates requests from instruction and data streams
// Connects core to peripherals and I/O pins on SOC
// Bus width presently matches XLEN
//
// Documentation: RISC-V System on Chip Design
//
// A component of the CORE-V-WALLY configurable RISC-V project.
// https://github.com/openhwgroup/cvw
//
// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
//
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
//
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file
// except in compliance with the License, or, at your option, the Apache License version 2.0. You
// may obtain a copy of the License at
//
// https://solderpad.org/licenses/SHL-2.1/
//
// Unless required by applicable law or agreed to in writing, any work distributed under the
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific language governing permissions
// and limitations under the License.
////////////////////////////////////////////////////////////////////////////////////////////////
module controllerinput #(
parameter PA_BITS,
parameter SAVE_ENABLED = 1 // 1: Save manager inputs if Save = 1, 0: Don't save inputs
)(
input logic HCLK,
input logic HRESETn,
input logic Save, // Two or more managers requesting (HTRANS != 00) at the same time. Save the non-granted manager inputs
input logic Restore, // Restore a saved manager inputs when it is finally granted
input logic Disable, // Suppress HREADY to the non-granted manager
output logic Request, // This manager is making a request
// controller input
input logic [1:0] HTRANSIn, // Manager input. AHB transaction type, 00: IDLE, 10 NON_SEQ, 11 SEQ
input logic HWRITEIn, // Manager input. AHB 0: Read operation 1: Write operation
input logic [2:0] HSIZEIn, // Manager input. AHB transaction width
input logic [2:0] HBURSTIn, // Manager input. AHB burst length
input logic [PA_BITS-1:0] HADDRIn, // Manager input. AHB address
output logic HREADYOut, // Indicate to manager the peripheral is not busy and another manager does not have priority
// controller output
output logic [1:0] HTRANSOut, // Arbitrated manager transaction. AHB transaction type, 00: IDLE, 10 NON_SEQ, 11 SEQ
output logic HWRITEOut, // Arbitrated manager transaction. AHB 0: Read operation 1: Write operation
output logic [2:0] HSIZEOut, // Arbitrated manager transaction. AHB transaction width
output logic [2:0] HBURSTOut, // Arbitrated manager transaction. AHB burst length
output logic [PA_BITS-1:0] HADDROut, // Arbitrated manager transaction. AHB address
input logic HREADYIn // Peripheral ready
);
logic HWRITESave;
logic [2:0] HSIZESave;
logic [2:0] HBURSTSave;
logic [1:0] HTRANSSave;
logic [PA_BITS-1:0] HADDRSave;
if (SAVE_ENABLED) begin
flopenr #(1+3+3+2+PA_BITS) SaveReg(HCLK, ~HRESETn, Save,
{HWRITEIn, HSIZEIn, HBURSTIn, HTRANSIn, HADDRIn},
{HWRITESave, HSIZESave, HBURSTSave, HTRANSSave, HADDRSave});
mux2 #(1+3+3+2+PA_BITS) RestorMux({HWRITEIn, HSIZEIn, HBURSTIn, HTRANSIn, HADDRIn},
{HWRITESave, HSIZESave, HBURSTSave, HTRANSSave, HADDRSave},
Restore,
{HWRITEOut, HSIZEOut, HBURSTOut, HTRANSOut, HADDROut});
end else begin
assign HWRITEOut = HWRITEIn;
assign HSIZEOut = HSIZEIn;
assign HBURSTOut = HBURSTIn;
assign HTRANSOut = HTRANSIn;
assign HADDROut = HADDRIn;
end
assign Request = HTRANSOut != 2'b00;
assign HREADYOut = HREADYIn & ~Disable;
endmodule