tinyriscv/rtl/core/ctrl.v

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/*
Copyright 2019 Blue Liang, liangkangnan@163.com
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
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.
*/
`include "defines.v"
module ctrl(
input wire rst,
input wire jump_flag_i,
input wire[`InstAddrBus] jump_addr_i,
input wire hold_flag_ex_i,
input wire hold_flag_rib_i,
input wire jtag_halt_flag_i,
input wire[`INT_BUS] int_flag_i,
input wire[`InstAddrBus] int_return_addr_i,
output reg[`Hold_Flag_Bus] hold_flag_o,
output reg jump_flag_o,
output reg[`InstAddrBus] jump_addr_o
);
always @ (*) begin
if (rst == `RstEnable) begin
hold_flag_o <= `Hold_None;
jump_flag_o <= `JumpDisable;
jump_addr_o <= `ZeroWord;
end else begin
jump_addr_o <= jump_addr_i;
jump_flag_o <= jump_flag_i;
hold_flag_o <= `Hold_None;
if (int_flag_i == `INT_TIMER0) begin
jump_addr_o <= `INT_TIMER0_ENTRY_ADDR;
jump_flag_o <= `JumpEnable;
hold_flag_o <= `Hold_Id;
end else if (int_flag_i == `INT_RET) begin
jump_addr_o <= int_return_addr_i;
jump_flag_o <= `JumpEnable;
hold_flag_o <= `Hold_Id;
end else if (jump_flag_i == `JumpEnable || hold_flag_ex_i == `HoldEnable) begin
hold_flag_o <= `Hold_Id;
end else if (hold_flag_rib_i == `HoldEnable) begin
hold_flag_o <= `Hold_Pc;
end else if (jtag_halt_flag_i == `HoldEnable) begin
hold_flag_o <= `Hold_Id;
end else begin
hold_flag_o <= `Hold_None;
end
end
end
endmodule