eth: Use shared counter for fractional part of pause quanta

Signed-off-by: Alex Forencich <alex@alexforencich.com>

rtl/eth/taxi_mac_pause_ctrl_rx.sv

@@ -81,8 +81,11 @@ if (MCF_PARAMS_SIZE < (PFC_EN ? 18 : 2))
 logic lfc_req_reg = 1'b0, lfc_req_next;
 logic [7:0] pfc_req_reg = 8'd0, pfc_req_next;
 
-logic [QW+QFB-1:0] lfc_quanta_reg = '0, lfc_quanta_next;
+logic [QFB-1:0] quanta_cnt_reg = '0, quanta_cnt_next;
-logic [QW+QFB-1:0] pfc_quanta_reg[0:7], pfc_quanta_next[0:7];
+logic [1:0] quanta_inc_reg = '0, quanta_inc_next;
+
+logic [QW-1:0] lfc_quanta_reg = '0, lfc_quanta_next;
+logic [QW-1:0] pfc_quanta_reg[8], pfc_quanta_next[8];
 
 logic stat_rx_lfc_pkt_reg = 1'b0, stat_rx_lfc_pkt_next;
 logic stat_rx_lfc_xon_reg = 1'b0, stat_rx_lfc_xon_next;
@@ -117,9 +120,15 @@ always_comb begin
     stat_rx_pfc_xon_next = '0;
     stat_rx_pfc_xoff_next = '0;
 
-    if (cfg_quanta_clk_en && rx_lfc_ack) begin
+    quanta_cnt_next = quanta_cnt_reg;
-        if (lfc_quanta_reg > (QW+QFB)'(cfg_quanta_step)) begin
+    quanta_inc_next = 0;
-            lfc_quanta_next = lfc_quanta_reg - (QW+QFB)'(cfg_quanta_step);
+    if (cfg_quanta_clk_en) begin
+        {quanta_inc_next, quanta_cnt_next} = (2+QFB)'(quanta_cnt_reg) + cfg_quanta_step;
+    end
+
+    if (rx_lfc_ack) begin
+        if (lfc_quanta_reg >= QW'(quanta_inc_reg)) begin
+            lfc_quanta_next = lfc_quanta_reg - QW'(quanta_inc_reg);
         end else begin
             lfc_quanta_next = '0;
         end
@@ -130,9 +139,9 @@ always_comb begin
     lfc_req_next = (lfc_quanta_reg != 0) && rx_lfc_en && cfg_rx_lfc_en;
 
     for (integer k = 0; k < 8; k = k + 1) begin
-        if (cfg_quanta_clk_en && rx_pfc_ack[k]) begin
+        if (rx_pfc_ack[k]) begin
-            if (pfc_quanta_reg[k] > (QW+QFB)'(cfg_quanta_step)) begin
+            if (pfc_quanta_reg[k] >= QW'(quanta_inc_reg)) begin
-                pfc_quanta_next[k] = pfc_quanta_reg[k] - (QW+QFB)'(cfg_quanta_step);
+                pfc_quanta_next[k] = pfc_quanta_reg[k] - QW'(quanta_inc_reg);
             end else begin
                 pfc_quanta_next[k] = '0;
             end
@@ -148,14 +157,14 @@ always_comb begin
             stat_rx_lfc_pkt_next = 1'b1;
             stat_rx_lfc_xon_next = {mcf_params[7:0], mcf_params[15:8]} == 0;
             stat_rx_lfc_xoff_next = {mcf_params[7:0], mcf_params[15:8]} != 0;
-            lfc_quanta_next = {mcf_params[7:0], mcf_params[15:8], {QFB{1'b0}}};
+            lfc_quanta_next = {mcf_params[7:0], mcf_params[15:8]};
         end else if (PFC_EN && mcf_opcode == cfg_rx_pfc_opcode && cfg_rx_pfc_en) begin
             stat_rx_pfc_pkt_next = 1'b1;
             for (integer k = 0; k < 8; k = k + 1) begin
                 if (mcf_params[k+8]) begin
                     stat_rx_pfc_xon_next[k] = {mcf_params[16+(k*QW)+0 +: 8], mcf_params[16+(k*QW)+8 +: 8]} == 0;
                     stat_rx_pfc_xoff_next[k] = {mcf_params[16+(k*QW)+0 +: 8], mcf_params[16+(k*QW)+8 +: 8]} != 0;
-                    pfc_quanta_next[k] = {mcf_params[16+(k*QW)+0 +: 8], mcf_params[16+(k*QW)+8 +: 8], {QFB{1'b0}}};
+                    pfc_quanta_next[k] = {mcf_params[16+(k*QW)+0 +: 8], mcf_params[16+(k*QW)+8 +: 8]};
                 end
             end
         end
@@ -166,6 +175,9 @@ always_ff @(posedge clk) begin
     lfc_req_reg <= lfc_req_next;
     pfc_req_reg <= pfc_req_next;
 
+    quanta_cnt_reg <= quanta_cnt_next;
+    quanta_inc_reg <= quanta_inc_next;
+
     lfc_quanta_reg <= lfc_quanta_next;
     for (integer k = 0; k < 8; k = k + 1) begin
         pfc_quanta_reg[k] <= pfc_quanta_next[k];

rtl/eth/taxi_mac_pause_ctrl_tx.sv

@@ -95,8 +95,11 @@ logic [7:0] pfc_act_reg = 8'd0, pfc_act_next;
 logic [7:0] pfc_en_reg = 8'd0, pfc_en_next;
 logic pfc_send_reg = 1'b0, pfc_send_next;
 
-logic [QW+QFB-1:0] lfc_refresh_reg = '0, lfc_refresh_next;
+logic [QFB-1:0] quanta_cnt_reg = '0, quanta_cnt_next;
-logic [QW+QFB-1:0] pfc_refresh_reg[0:7], pfc_refresh_next[0:7];
+logic [1:0] quanta_inc_reg = '0, quanta_inc_next;
+
+logic [QW-1:0] lfc_refresh_reg = '0, lfc_refresh_next;
+logic [QW-1:0] pfc_refresh_reg[8], pfc_refresh_next[8];
 
 logic stat_tx_lfc_pkt_reg = 1'b0, stat_tx_lfc_pkt_next;
 logic stat_tx_lfc_xon_reg = 1'b0, stat_tx_lfc_xon_next;
@@ -168,31 +171,29 @@ always_comb begin
     stat_tx_pfc_xon_next = '0;
     stat_tx_pfc_xoff_next = '0;
 
+    quanta_cnt_next = quanta_cnt_reg;
+    quanta_inc_next = 0;
     if (cfg_quanta_clk_en) begin
-        if (lfc_refresh_reg > (QW+QFB)'(cfg_quanta_step)) begin
+        {quanta_inc_next, quanta_cnt_next} = (2+QFB)'(quanta_cnt_reg) + cfg_quanta_step;
-            lfc_refresh_next = lfc_refresh_reg - (QW+QFB)'(cfg_quanta_step);
+    end
-        end else begin
+
-            lfc_refresh_next = '0;
+    if (lfc_refresh_reg >= QW'(quanta_inc_reg)) begin
-            if (lfc_req_reg) begin
+        lfc_refresh_next = lfc_refresh_reg - QW'(quanta_inc_reg);
-                lfc_send_next = 1'b1;
-            end
-        end
     end else begin
-        lfc_refresh_next = lfc_refresh_reg;
+        lfc_refresh_next = '0;
+        if (lfc_req_reg) begin
+            lfc_send_next = 1'b1;
+        end
     end
 
     for (integer k = 0; k < 8; k = k + 1) begin
-        if (cfg_quanta_clk_en) begin
+        if (pfc_refresh_reg[k] >= QW'(quanta_inc_reg)) begin
-            if (pfc_refresh_reg[k] > (QW+QFB)'(cfg_quanta_step)) begin
+            pfc_refresh_next[k] = pfc_refresh_reg[k] - QW'(quanta_inc_reg);
-                pfc_refresh_next[k] = pfc_refresh_reg[k] - (QW+QFB)'(cfg_quanta_step);
-            end else begin
-                pfc_refresh_next[k] = 0;
-                if (pfc_req_reg[k]) begin
-                    pfc_send_next = 1'b1;
-                end
-            end
         end else begin
-            pfc_refresh_next[k] = pfc_refresh_reg[k];
+            pfc_refresh_next[k] = '0;
+            if (pfc_req_reg[k]) begin
+                pfc_send_next = 1'b1;
+            end
         end
     end
 
@@ -208,7 +209,7 @@ always_comb begin
                 mcf_pfc_sel_next = 1'b0;
                 mcf_valid_next = lfc_act_reg;
                 lfc_act_next = lfc_req_reg;
-                lfc_refresh_next = lfc_req_reg ? {cfg_tx_lfc_refresh, {QFB{1'b0}}} : '0;
+                lfc_refresh_next = lfc_req_reg ? cfg_tx_lfc_refresh : '0;
                 lfc_send_next = 1'b0;
 
                 stat_tx_lfc_pkt_next = lfc_act_reg;
@@ -232,7 +233,7 @@ always_comb begin
                 pfc_en_next = pfc_act_reg;
                 pfc_act_next = pfc_req_reg;
                 for (integer k = 0; k < 8; k = k + 1) begin
-                    pfc_refresh_next[k] = pfc_req_reg[k] ? {cfg_tx_pfc_refresh[k], {QFB{1'b0}}} : '0;
+                    pfc_refresh_next[k] = pfc_req_reg[k] ? cfg_tx_pfc_refresh[k] : '0;
                 end
                 pfc_send_next = 1'b0;
 
@@ -256,6 +257,9 @@ always_ff @(posedge clk) begin
     mcf_pfc_sel_reg <= mcf_pfc_sel_next;
     mcf_valid_reg <= mcf_valid_next;
 
+    quanta_cnt_reg <= quanta_cnt_next;
+    quanta_inc_reg <= quanta_inc_next;
+
     lfc_refresh_reg <= lfc_refresh_next;
     for (integer k = 0; k < 8; k = k + 1) begin
         pfc_refresh_reg[k] <= pfc_refresh_next[k];

tb/eth/taxi_eth_mac_10g/test_taxi_eth_mac_10g.py

@@ -607,6 +607,8 @@ async def run_test_pfc(dut, ifg=12):
             test_frame = XgmiiFrame.from_payload(bytes(test_pkt))
             await tb.xgmii_source.send(test_frame)
 
+    dut.rx_pfc_ack.value = 0xff
+
     for i in range(8):
         for k in range(200):
             await RisingEdge(dut.tx_clk)

tb/eth/taxi_eth_mac_1g/test_taxi_eth_mac_1g.py

@@ -623,7 +623,7 @@ async def run_test_pfc(dut, ifg=12, enable_gen=None, mii_sel=True):
     dut.tx_pfc_req.value = 0x00
     dut.tx_pfc_resend.value = 0
     dut.rx_pfc_en.value = 0xff
-    dut.rx_pfc_ack.value = 0
+    dut.rx_pfc_ack.value = 0x00
 
     dut.tx_lfc_pause_en.value = 0
     dut.tx_pause_req.value = 0
@@ -682,6 +682,8 @@ async def run_test_pfc(dut, ifg=12, enable_gen=None, mii_sel=True):
             test_frame = GmiiFrame.from_payload(bytes(test_pkt))
             await tb.gmii_source.send(test_frame)
 
+    dut.rx_pfc_ack.value = 0xff
+
     for i in range(8):
         for k in range(500):
             await RisingEdge(dut.tx_clk)

tb/eth/taxi_eth_mac_1g_gmii/test_taxi_eth_mac_1g_gmii.py

@@ -487,7 +487,7 @@ async def run_test_pfc(dut, ifg=12, speed=1000e6):
     dut.tx_pfc_req.value = 0x00
     dut.tx_pfc_resend.value = 0
     dut.rx_pfc_en.value = 0xff
-    dut.rx_pfc_ack.value = 0
+    dut.rx_pfc_ack.value = 0x00
 
     dut.tx_lfc_pause_en.value = 0
     dut.tx_pause_req.value = 0
@@ -546,6 +546,8 @@ async def run_test_pfc(dut, ifg=12, speed=1000e6):
             test_frame = GmiiFrame.from_payload(bytes(test_pkt))
             await tb.gmii_phy.rx.send(test_frame)
 
+    dut.rx_pfc_ack.value = 0xff
+
     for i in range(8):
         for k in range(500):
             await RisingEdge(dut.tx_clk)

tb/eth/taxi_eth_mac_1g_rgmii/test_taxi_eth_mac_1g_rgmii.py

@@ -490,7 +490,7 @@ async def run_test_pfc(dut, ifg=12, speed=1000e6):
     dut.tx_pfc_req.value = 0x00
     dut.tx_pfc_resend.value = 0
     dut.rx_pfc_en.value = 0xff
-    dut.rx_pfc_ack.value = 0
+    dut.rx_pfc_ack.value = 0x00
 
     dut.tx_lfc_pause_en.value = 0
     dut.tx_pause_req.value = 0
@@ -549,6 +549,8 @@ async def run_test_pfc(dut, ifg=12, speed=1000e6):
             test_frame = GmiiFrame.from_payload(bytes(test_pkt))
             await tb.rgmii_phy.rx.send(test_frame)
 
+    dut.rx_pfc_ack.value = 0xff
+
     for i in range(8):
         for k in range(500):
             await RisingEdge(dut.rx_clk)

tb/eth/taxi_eth_mac_mii/test_taxi_eth_mac_mii.py

@@ -451,7 +451,7 @@ async def run_test_pfc(dut, ifg=12, speed=1000e6):
     dut.tx_pfc_req.value = 0x00
     dut.tx_pfc_resend.value = 0
     dut.rx_pfc_en.value = 0xff
-    dut.rx_pfc_ack.value = 0
+    dut.rx_pfc_ack.value = 0x00
 
     dut.tx_lfc_pause_en.value = 0
     dut.tx_pause_req.value = 0
@@ -510,6 +510,8 @@ async def run_test_pfc(dut, ifg=12, speed=1000e6):
             test_frame = GmiiFrame.from_payload(bytes(test_pkt))
             await tb.mii_phy.rx.send(test_frame)
 
+    dut.rx_pfc_ack.value = 0xff
+
     for i in range(8):
         for k in range(500):
             await RisingEdge(dut.tx_clk)

tb/eth/taxi_eth_mac_phy_10g/test_taxi_eth_mac_phy_10g.py

@@ -668,6 +668,8 @@ async def run_test_pfc(dut, ifg=12):
             test_frame = XgmiiFrame.from_payload(bytes(test_pkt))
             await tb.serdes_source.send(test_frame)
 
+    dut.rx_pfc_ack.value = 0xff
+
     for i in range(8):
         for k in range(200):
             await RisingEdge(dut.tx_clk)

tb/eth/taxi_mac_pause_ctrl_rx/test_taxi_mac_pause_ctrl_rx.py

@@ -121,7 +121,7 @@ async def run_test_lfc(dut):
     tb.log.info("pause time   : %g s", pause_time)
     tb.log.info("pause quanta : %f", pause_quanta)
 
-    assert round(pause_quanta) == 100
+    assert round(pause_quanta/4) == 100//4
 
     tb.log.info("Test release time accuracy (with refresh)")
     eth = Ether(src='5A:51:52:53:54:55', dst='01:80:C2:00:00:01', type=0x8808)
@@ -151,7 +151,7 @@ async def run_test_lfc(dut):
     tb.log.info("pause time   : %g s", pause_time)
     tb.log.info("pause quanta : %f", pause_quanta)
 
-    assert round(pause_quanta) == 100
+    assert round(pause_quanta/4) == 100//4
 
     tb.log.info("Test explicit release")
     eth = Ether(src='5A:51:52:53:54:55', dst='01:80:C2:00:00:01', type=0x8808)
@@ -230,7 +230,7 @@ async def run_test_pfc(dut):
     tb.log.info("pause time   : %g s", pause_time)
     tb.log.info("pause quanta : %f", pause_quanta)
 
-    assert round(pause_quanta) == 100
+    assert round(pause_quanta/4) == 100//4
 
     tb.log.info("Test release time accuracy (with refresh)")
     eth = Ether(src='5A:51:52:53:54:55', dst='01:80:C2:00:00:01', type=0x8808)
@@ -260,7 +260,7 @@ async def run_test_pfc(dut):
     tb.log.info("pause time   : %g s", pause_time)
     tb.log.info("pause quanta : %f", pause_quanta)
 
-    assert round(pause_quanta) == 100
+    assert round(pause_quanta/4) == 100//4
 
     tb.log.info("Test explicit release")
     eth = Ether(src='5A:51:52:53:54:55', dst='01:80:C2:00:00:01', type=0x8808)
@@ -316,7 +316,7 @@ async def run_test_pfc(dut):
         tb.log.info("pause time   : %g s", pause_time)
         tb.log.info("pause quanta : %f", pause_quanta)
 
-        assert round(pause_quanta) == (k+1)*10
+        assert round(pause_quanta/4) == (k+1)*10//4
 
     dut.rx_pfc_ack.value = 0
 
@@ -358,7 +358,7 @@ async def run_test_pfc(dut):
     tb.log.info("pause time   : %g s", pause_time)
     tb.log.info("pause quanta : %f", pause_quanta)
 
-    assert round(pause_quanta) == 100
+    assert round(pause_quanta/4) == 100//4
 
     await RisingEdge(dut.clk)
     await RisingEdge(dut.clk)

tb/eth/taxi_mac_pause_ctrl_tx/test_taxi_mac_pause_ctrl_tx.py

@@ -143,7 +143,7 @@ async def run_test_lfc(dut):
             tb.log.info("refresh time   : %g s", refresh_time)
             tb.log.info("refresh quanta : %f", refresh_quanta)
 
-            assert round(refresh_quanta) == 100
+            assert round(refresh_quanta/4) == 100//4
 
         start_time = get_sim_time('sec')
 
@@ -216,7 +216,7 @@ async def run_test_pfc(dut):
             tb.log.info("refresh time   : %g s", refresh_time)
             tb.log.info("refresh quanta : %f", refresh_quanta)
 
-            assert round(refresh_quanta) == 100
+            assert round(refresh_quanta/4) == 100//4
 
         start_time = get_sim_time('sec')
 
@@ -248,7 +248,7 @@ async def run_test_pfc(dut):
                 tb.log.info("refresh time   : %g s", refresh_time)
                 tb.log.info("refresh quanta : %f", refresh_quanta)
 
-                assert round(refresh_quanta) == 100
+                assert round(refresh_quanta/4) == 100//4
 
             start_time = get_sim_time('sec')
 
@@ -301,7 +301,7 @@ async def run_test_pfc(dut):
             tb.log.info("refresh time   : %g s", refresh_time)
             tb.log.info("refresh quanta : %f", refresh_quanta)
 
-            assert round(refresh_quanta) == 100
+            assert round(refresh_quanta/4) == 100//4
 
         start_time = get_sim_time('sec')