dma rework

This commit is contained in:
Mateusz Faderewski 2024-07-15 20:28:11 +02:00
parent 64f78e040a
commit cab8ac521a
2 changed files with 349 additions and 171 deletions

View File

@ -8,227 +8,405 @@ module memory_dma (
mem_bus.controller mem_bus mem_bus.controller mem_bus
); );
// DMA start/stop control // Start/stop logic
logic dma_start; logic dma_start;
logic dma_stop; logic dma_stop;
logic dma_stop_requested;
always_comb begin
dma_start = dma_scb.start && !dma_scb.stop && !dma_scb.busy;
dma_stop = dma_scb.stop;
end
always_ff @(posedge clk) begin always_ff @(posedge clk) begin
if (reset) begin dma_start <= 1'b0;
dma_stop_requested <= 1'b0; if (dma_scb.stop) begin
end else begin dma_stop <= 1'b1;
if (dma_stop) begin end else if (dma_scb.start) begin
dma_stop_requested <= 1'b1; dma_start <= 1'b1;
end dma_stop <= 1'b0;
if (dma_start) begin
dma_stop_requested <= 1'b0;
end
end end
end end
// Remaining counter and FIFO enable // Memory bus controller
logic [26:0] remaining; typedef enum bit [1:0] {
logic trx_enabled; MEM_BUS_STATE_IDLE,
MEM_BUS_STATE_WAIT,
MEM_BUS_STATE_TRANSFER
} e_mem_bus_state;
e_mem_bus_state mem_bus_state;
e_mem_bus_state next_mem_bus_state;
logic mem_bus_wdata_buffer_ready;
// logic mem_bus_wdata_buffer_ack;
// logic [1:0] mem_bus_wmask_buffer;
logic [1:0] mem_bus_wdata_valid;
logic [15:0] mem_bus_wdata_buffer;
logic mem_bus_rdata_ready;
logic mem_bus_rdata_ack;
logic mem_bus_rdata_end;
logic [1:0] mem_bus_rdata_valid;
logic [15:0] mem_bus_rdata_buffer;
logic [26:0] mem_bus_remaining_bytes;
logic mem_bus_last_transfer;
logic mem_bus_almost_last_transfer;
logic mem_bus_unaligned_start;
logic mem_bus_unaligned_end;
always_ff @(posedge clk) begin
if (reset) begin
mem_bus_state <= MEM_BUS_STATE_IDLE;
end else begin
mem_bus_state <= next_mem_bus_state;
end
end
always_comb begin always_comb begin
trx_enabled = remaining > 27'd0; next_mem_bus_state = mem_bus_state;
mem_bus_last_transfer = (mem_bus_remaining_bytes == 27'd0);
mem_bus_almost_last_transfer = (mem_bus_remaining_bytes <= 27'd2);
case (mem_bus_state)
MEM_BUS_STATE_IDLE: begin
if (dma_start) begin
next_mem_bus_state = MEM_BUS_STATE_WAIT;
end
end
MEM_BUS_STATE_WAIT: begin
if (dma_stop || mem_bus_last_transfer) begin
next_mem_bus_state = MEM_BUS_STATE_IDLE;
end else if (mem_bus_wdata_buffer_ready || mem_bus_rdata_ready) begin
next_mem_bus_state = MEM_BUS_STATE_TRANSFER;
end
end
MEM_BUS_STATE_TRANSFER: begin
if (mem_bus.ack) begin
if (dma_stop || mem_bus_last_transfer) begin
next_mem_bus_state = MEM_BUS_STATE_IDLE;
end else if (!(mem_bus_wdata_buffer_ready || mem_bus_rdata_ready)) begin
next_mem_bus_state = MEM_BUS_STATE_WAIT;
end
end
end
default: begin
next_mem_bus_state = MEM_BUS_STATE_IDLE;
end
endcase
end end
always_ff @(posedge clk) begin
mem_bus_rdata_ack <= 1'b0;
if (mem_bus.ack) begin
mem_bus.request <= 1'b0;
mem_bus.address <= (mem_bus.address + 26'd2);
mem_bus_rdata_ack <= 1'b1;
mem_bus_rdata_end <= mem_bus_last_transfer;
mem_bus_rdata_valid <= mem_bus.wmask;
mem_bus_rdata_buffer <= mem_bus.rdata;
end
case (mem_bus_state)
MEM_BUS_STATE_IDLE: begin
mem_bus.request <= 1'b0;
mem_bus_rdata_end <= 1'b1;
if (dma_start) begin
mem_bus.write <= dma_scb.direction;
mem_bus.address <= {dma_scb.starting_address[26:1], 1'b0};
mem_bus_remaining_bytes <= dma_scb.transfer_length;
mem_bus_unaligned_start <= dma_scb.starting_address[0];
mem_bus_unaligned_end <= (dma_scb.starting_address[0] ^ dma_scb.transfer_length[0]);
mem_bus_rdata_end <= 1'b0;
end
end
MEM_BUS_STATE_WAIT: begin
if (!dma_stop && !mem_bus_last_transfer) begin
if (mem_bus_wdata_buffer_ready || mem_bus_rdata_ready) begin
mem_bus.request <= 1'b1;
mem_bus_unaligned_start <= 1'b0;
mem_bus.wdata <= (dma_scb.byte_swap ? {mem_bus_wdata_buffer[7:0], mem_bus_wdata_buffer[15:8]} : mem_bus_wdata_buffer);
mem_bus.wmask <= 2'b11;
mem_bus_remaining_bytes <= (mem_bus_remaining_bytes - 27'd2);
if (mem_bus_unaligned_end && mem_bus_almost_last_transfer) begin
mem_bus.wmask <= 2'b10;
mem_bus_remaining_bytes <= (mem_bus_remaining_bytes - 27'd1);
end
if (mem_bus_unaligned_start) begin
mem_bus.wmask <= 2'b01;
mem_bus_remaining_bytes <= (mem_bus_remaining_bytes - 27'd1);
end
end
end
end
MEM_BUS_STATE_TRANSFER: begin
if (!dma_stop && !mem_bus_last_transfer) begin
if (mem_bus.ack && (mem_bus_wdata_buffer_ready || mem_bus_rdata_ready)) begin
mem_bus.request <= 1'b1;
mem_bus.wdata <= (dma_scb.byte_swap ? {mem_bus_wdata_buffer[7:0], mem_bus_wdata_buffer[15:8]} : mem_bus_wdata_buffer);
mem_bus.wmask <= 2'b11;
mem_bus_remaining_bytes <= (mem_bus_remaining_bytes - 27'd2);
if (mem_bus_unaligned_end && mem_bus_almost_last_transfer) begin
mem_bus.wmask <= 2'b10;
mem_bus_remaining_bytes <= (mem_bus_remaining_bytes - 27'd1);
end
end
end
end
default: begin end
endcase
end
assign mem_bus_wdata_buffer_ready = 1'b0;
// assign mem_bus_rdata_ready = 1'b1;
// RX FIFO controller // RX FIFO controller
logic [1:0] rx_wmask; // typedef enum bit [1:0] {
logic rx_rdata_pop; // RX_FIFO_BUS_STATE_IDLE,
logic rx_rdata_shift; // RX_FIFO_BUS_STATE_TRANSFER_1,
logic rx_rdata_valid; // RX_FIFO_BUS_STATE_TRANSFER_2,
logic [15:0] rx_buffer; // RX_FIFO_BUS_STATE_WAIT
logic rx_buffer_valid; // } e_rx_fifo_bus_state;
logic [1:0] rx_buffer_counter;
logic [1:0] rx_buffer_valid_counter; // e_rx_fifo_bus_state rx_fifo_bus_state;
// e_rx_fifo_bus_state next_rx_fifo_bus_state;
// logic rx_fifo_read_delayed;
// logic rx_fifo_buffer_shift;
// logic rx_fifo_unaligned_start;
// logic rx_fifo_unaligned_end;
always_ff @(posedge clk) begin
// if (reset || dma_stop) begin
// rx_fifo_bus_state <= RX_FIFO_BUS_STATE_IDLE;
// end else begin
// rx_fifo_bus_state <= next_rx_fifo_bus_state;
// end
end
always_comb begin always_comb begin
rx_buffer_valid = rx_buffer_valid_counter == 2'd2; // next_rx_fifo_bus_state = rx_fifo_bus_state;
// fifo_bus.rx_read = 1'b0;
// rx_fifo_buffer_shift = 1'b0;
// case (rx_fifo_bus_state)
// RX_FIFO_BUS_STATE_IDLE: begin
// if (dma_start && dma_scb.direction) begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_TRANSFER_1;
// if (dma_scb.starting_address[0]) begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_TRANSFER_2;
// end
// end
// end
// RX_FIFO_BUS_STATE_TRANSFER_1,
// RX_FIFO_BUS_STATE_TRANSFER_2: begin
// fifo_bus.rx_read = (!no_bytes_left && !fifo_bus.rx_empty);
// rx_fifo_buffer_shift = no_bytes_left;
// if (fifo_bus.rx_read || no_bytes_left) begin
// if (rx_fifo_bus_state == RX_FIFO_BUS_STATE_TRANSFER_1) begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_TRANSFER_2;
// end else begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_WAIT;
// end
// end
// end
// RX_FIFO_BUS_STATE_WAIT: begin
// if (mem_bus_wdata_buffer_ready && mem_bus_wdata_buffer_ack) begin
// if (no_bytes_left) begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_IDLE;
// end else begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_TRANSFER_1;
// end
// end
// end
// default: begin
// next_rx_fifo_bus_state = RX_FIFO_BUS_STATE_IDLE;
// end
// endcase
end end
always_ff @(posedge clk) begin always_ff @(posedge clk) begin
rx_rdata_pop <= ( // rx_fifo_read_delayed <= (fifo_bus.rx_read || rx_fifo_buffer_shift);
!rx_rdata_pop &&
!fifo_bus.rx_read &&
trx_enabled &&
rx_buffer_counter < 2'd2 &&
!fifo_bus.rx_empty &&
mem_bus.write
);
rx_rdata_shift <= 1'b0;
fifo_bus.rx_read <= rx_rdata_pop;
rx_rdata_valid <= fifo_bus.rx_read;
if (dma_start) begin // if (rx_fifo_read_delayed) begin
if (dma_scb.starting_address[0]) begin // mem_bus_wdata_buffer <= {mem_bus_wdata_buffer[7:0], fifo_bus.rx_rdata};
rx_wmask <= 2'b01; // end
rx_buffer_counter <= 2'd1;
rx_buffer_valid_counter <= 2'd1;
end else begin
rx_wmask <= 2'b11;
rx_buffer_counter <= 2'd0;
rx_buffer_valid_counter <= 2'd0;
end
end
if (rx_rdata_pop) begin // case (rx_fifo_bus_state)
rx_buffer_counter <= rx_buffer_counter + 1'd1; // RX_FIFO_BUS_STATE_IDLE: begin
end // mem_bus_wdata_buffer_ready <= 1'b0;
// if (dma_start) begin
// mem_bus_rx_transfer_end <= 1'b0;
// rx_fifo_unaligned_start <= dma_scb.starting_address[0];
// rx_fifo_unaligned_end <= (dma_scb.starting_address[0] ^ dma_scb.transfer_length[0]);
// end
// end
if (rx_rdata_shift || rx_rdata_valid) begin // RX_FIFO_BUS_STATE_TRANSFER_1,
if (dma_scb.byte_swap) begin // RX_FIFO_BUS_STATE_TRANSFER_2: begin end
rx_buffer <= {fifo_bus.rx_rdata, rx_buffer[15:8]};
end else begin
rx_buffer <= {rx_buffer[7:0], fifo_bus.rx_rdata};
end
rx_buffer_valid_counter <= rx_buffer_valid_counter + 1'd1;
if (remaining == 27'd0 && rx_buffer_counter == 2'd1) begin
rx_wmask <= 2'b10;
rx_rdata_shift <= 1'b1;
rx_buffer_counter <= rx_buffer_counter + 1'd1;
end
end
if (rx_buffer_valid && !mem_bus.request) begin // RX_FIFO_BUS_STATE_WAIT: begin
rx_wmask <= 2'b11; // mem_bus_wdata_buffer_ready <= 1'b1;
rx_buffer_counter <= 2'd0; // mem_bus_wmask_buffer <= 2'b11;
rx_buffer_valid_counter <= 2'd0; // if (rx_fifo_unaligned_start) begin
end // mem_bus_wmask_buffer <= 2'b01;
// end
// if (no_bytes_left) begin
// mem_bus_rx_transfer_end <= 1'b1;
// if (rx_fifo_unaligned_end) begin
// mem_bus_wmask_buffer <= 2'b10;
// end
// end
// if (mem_bus_wdata_buffer_ack) begin
// rx_fifo_unaligned_start <= 1'b0;
// mem_bus_wdata_buffer_ready <= 1'b0;
// end
// end
// default: begin end
// endcase
end end
// TX FIFO controller // TX FIFO controller
logic tx_wdata_push; typedef enum bit [1:0] {
logic tx_wdata_first_push; TX_FIFO_BUS_STATE_IDLE,
logic [7:0] tx_buffer; TX_FIFO_BUS_STATE_WAIT,
logic tx_buffer_counter; TX_FIFO_BUS_STATE_TRANSFER_1,
logic tx_buffer_ready; TX_FIFO_BUS_STATE_TRANSFER_2
logic tx_buffer_valid; } e_tx_fifo_bus_state;
e_tx_fifo_bus_state tx_fifo_bus_state;
e_tx_fifo_bus_state next_tx_fifo_bus_state;
logic tx_fifo_shift;
logic tx_fifo_waiting;
logic [1:0] tx_fifo_valid;
logic [15:0] tx_fifo_buffer;
always_ff @(posedge clk) begin
if (reset || dma_stop) begin
tx_fifo_bus_state <= TX_FIFO_BUS_STATE_IDLE;
end else begin
tx_fifo_bus_state <= next_tx_fifo_bus_state;
end
end
always_comb begin always_comb begin
fifo_bus.tx_write = tx_wdata_push; next_tx_fifo_bus_state = tx_fifo_bus_state;
end
always_ff @(posedge clk) begin tx_fifo_shift = 1'b0;
tx_wdata_push <= (
!tx_wdata_push &&
trx_enabled &&
tx_buffer_valid &&
!fifo_bus.tx_full &&
!mem_bus.write
);
if (reset || dma_stop) begin fifo_bus.tx_write = 1'b0;
tx_buffer_ready <= 1'b0; fifo_bus.tx_wdata = tx_fifo_buffer[15:8];
tx_buffer_valid <= 1'b0;
end
if (dma_start) begin case (tx_fifo_bus_state)
tx_wdata_first_push <= 1'b1; TX_FIFO_BUS_STATE_IDLE: begin
tx_buffer_ready <= 1'b1; if (dma_start && !dma_scb.direction) begin
tx_buffer_valid <= 1'b0; next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_WAIT;
end end
if (tx_buffer_ready && mem_bus.request) begin
tx_buffer_ready <= 1'b0;
end
if (mem_bus.ack) begin
tx_wdata_first_push <= 1'b0;
tx_buffer_counter <= 1'd1;
tx_buffer_valid <= 1'b1;
{fifo_bus.tx_wdata, tx_buffer} <= mem_bus.rdata;
if (tx_wdata_first_push && dma_scb.starting_address[0]) begin
fifo_bus.tx_wdata <= mem_bus.rdata[7:0];
tx_buffer_counter <= 1'd0;
end
end
if (tx_wdata_push) begin
tx_buffer_counter <= tx_buffer_counter - 1'd1;
fifo_bus.tx_wdata <= tx_buffer;
if (tx_buffer_counter == 1'd0) begin
tx_buffer_ready <= 1'b1;
tx_buffer_valid <= 1'b0;
end
end
end
// Remaining counter controller
always_ff @(posedge clk) begin
if (reset || dma_stop) begin
remaining <= 27'd0;
end else begin
if (dma_start) begin
remaining <= dma_scb.transfer_length;
end end
if (!dma_stop_requested && ((mem_bus.write && rx_rdata_pop) || (!mem_bus.write && tx_wdata_push))) begin TX_FIFO_BUS_STATE_WAIT: begin
remaining <= remaining - 1'd1; if (mem_bus_rdata_ack || tx_fifo_waiting) begin
next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_TRANSFER_1;
end else if (mem_bus_rdata_end) begin
next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_IDLE;
end
end end
end
end
TX_FIFO_BUS_STATE_TRANSFER_1: begin
fifo_bus.tx_write = (!fifo_bus.tx_full && tx_fifo_valid[1]);
if (fifo_bus.tx_write || !tx_fifo_valid[1]) begin
next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_TRANSFER_2;
tx_fifo_shift = 1'b1;
end
end
// Mem bus controller TX_FIFO_BUS_STATE_TRANSFER_2: begin
fifo_bus.tx_write = (!fifo_bus.tx_full && tx_fifo_valid[1]);
always_ff @(posedge clk) begin if (fifo_bus.tx_write || !tx_fifo_valid[1]) begin
dma_scb.busy <= mem_bus.request || trx_enabled; next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_WAIT;
end tx_fifo_shift = 1'b1;
if (!mem_bus_rdata_ack && !tx_fifo_waiting && mem_bus_rdata_end) begin
always_ff @(posedge clk) begin next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_IDLE;
if (reset) begin
mem_bus.request <= 1'b0;
end else begin
if (!mem_bus.request) begin
if (mem_bus.write) begin
if (rx_buffer_valid) begin
mem_bus.request <= 1'b1;
mem_bus.wmask <= rx_wmask;
mem_bus.wdata <= rx_buffer;
end
end else begin
if (tx_buffer_ready) begin
mem_bus.request <= 1'b1;
end end
end end
end end
end
if (mem_bus.ack) begin default: begin
mem_bus.request <= 1'b0; next_tx_fifo_bus_state = TX_FIFO_BUS_STATE_IDLE;
end end
endcase
end end
always_ff @(posedge clk) begin always_ff @(posedge clk) begin
if (dma_start) begin if (tx_fifo_shift) begin
mem_bus.write <= dma_scb.direction; tx_fifo_valid <= {tx_fifo_valid[0], 1'bX};
tx_fifo_buffer <= {tx_fifo_buffer[7:0], 8'hXX};
end end
case (tx_fifo_bus_state)
TX_FIFO_BUS_STATE_IDLE: begin
mem_bus_rdata_ready <= 1'b0;
tx_fifo_waiting <= 1'b0;
if (dma_start) begin
mem_bus_rdata_ready <= !dma_scb.direction;
end
end
TX_FIFO_BUS_STATE_WAIT: begin
if (mem_bus_rdata_ack || tx_fifo_waiting) begin
mem_bus_rdata_ready <= 1'b0;
tx_fifo_waiting <= 1'b0;
tx_fifo_valid <= mem_bus_rdata_valid;
tx_fifo_buffer <= mem_bus_rdata_buffer;
end
end
TX_FIFO_BUS_STATE_TRANSFER_1: begin
if (mem_bus_rdata_ack) begin
tx_fifo_waiting <= 1'b1;
end
end
TX_FIFO_BUS_STATE_TRANSFER_2: begin
if (mem_bus_rdata_ack) begin
tx_fifo_waiting <= 1'b1;
end
if (fifo_bus.tx_write || !tx_fifo_valid[1]) begin
mem_bus_rdata_ready <= !mem_bus_rdata_end;
end
end
default: begin end
endcase
end end
always_ff @(posedge clk) begin
if (dma_start) begin
mem_bus.address <= {dma_scb.starting_address[26:1], 1'b0};
end
if (mem_bus.ack) begin // DMA busy indicator
mem_bus.address <= mem_bus.address + 27'd2;
end always_ff @(posedge clk) begin
dma_scb.busy <= (
(dma_scb.start && !dma_scb.stop) ||
dma_start ||
(mem_bus_state != MEM_BUS_STATE_IDLE) ||
// (rx_fifo_bus_state != RX_FIFO_BUS_STATE_IDLE) ||
(tx_fifo_bus_state != TX_FIFO_BUS_STATE_IDLE)
);
end end
endmodule endmodule

View File

@ -25,7 +25,7 @@ module usb_ft1248 (
fifo_8kb fifo_8kb_rx_inst ( fifo_8kb fifo_8kb_rx_inst (
.clk(clk), .clk(clk),
.reset(reset || fifo_flush), .reset(fifo_flush),
.empty(fifo_bus.rx_empty), .empty(fifo_bus.rx_empty),
.read(fifo_bus.rx_read), .read(fifo_bus.rx_read),
@ -40,7 +40,7 @@ module usb_ft1248 (
fifo_8kb fifo_8kb_tx_inst ( fifo_8kb fifo_8kb_tx_inst (
.clk(clk), .clk(clk),
.reset(reset || fifo_flush), .reset(fifo_flush),
.empty(tx_empty), .empty(tx_empty),
.read(tx_read), .read(tx_read),