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`include "cache/defs.sv"
module cache_routing
(
input logic clk,
rst_n,
input word core_address,
input logic core_read,
core_write,
input line core_writedata_line,
input line_be core_byteenable_line,
output logic core_waitrequest,
output line core_readdata_line,
output addr_tag core_tag,
output addr_index core_index,
output addr_offset core_offset,
input line data_rd,
input logic cache_core_waitrequest,
output logic cache_core_read,
cache_core_write,
input word cache_mem_address,
input logic cache_mem_read,
cache_mem_write,
input line cache_mem_writedata,
output logic cache_mem_waitrequest,
input logic mem_waitrequest,
input line mem_readdata,
output word mem_address,
output logic mem_read,
mem_write,
output line mem_writedata,
output line_be mem_byteenable
);
word core_address_line;
logic cached, cache_mem, transition;
addr_mbz mbz;
addr_io_region io;
enum int unsigned
{
IDLE,
CACHE,
BYPASS
} state;
assign cached = io == 3'b000;
assign cache_mem = cache_mem_read || cache_mem_write;
assign {io, core_tag, core_index, core_offset, mbz} = core_address;
assign core_address_line = {io, core_tag, core_index, 4'b0000};
assign core_readdata_line = cached ? data_rd : mem_readdata;
assign cache_core_read = core_read && cached;
assign cache_core_write = core_write && cached;
always_comb begin
transition = 0;
core_waitrequest = cache_core_waitrequest;
cache_mem_waitrequest = 1;
unique case (state)
IDLE:
transition = cache_mem || (!cached && (core_read || core_write));
CACHE:
cache_mem_waitrequest = mem_waitrequest;
BYPASS:
core_waitrequest = mem_waitrequest;
endcase
end
always_ff @(posedge clk or negedge rst_n)
if (!rst_n) begin
state <= IDLE;
mem_read <= 0;
mem_write <= 0;
end else unique case (state)
IDLE:
if (transition) begin
state <= cache_mem ? CACHE : BYPASS;
mem_read <= cache_mem ? cache_mem_read : core_read;
mem_write <= cache_mem ? cache_mem_write : core_write;
end
CACHE, BYPASS:
if (!mem_waitrequest) begin
state <= IDLE;
mem_read <= 0;
mem_write <= 0;
end
endcase
always_ff @(posedge clk)
if (transition) begin
mem_address <= cache_mem ? cache_mem_address : core_address_line;
mem_writedata <= cache_mem ? cache_mem_writedata : core_writedata_line;
mem_byteenable <= cache_mem ? 16'hff : core_byteenable_line;
end
endmodule
|
