jesd204: Handle sysref events in the register map

There are currently two sysref related events. One the sysref captured
event which is generated when an external sysref edge has been observed.
The other is the sysref alignment error event which is generated when a
sysref edge is observed that has a different alignment from previously
observed sysref edges.

Capture those events in the register map. This is useful for error
diagnostic. The events are sticky and write-1-to-clear.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

library/jesd204/axi_jesd204_common/jesd204_up_sysref.v

@@ -61,12 +61,37 @@ module jesd204_up_sysref (
   output reg [7:0] up_cfg_lmfc_offset,
   output reg up_cfg_sysref_disable,
 
-  input core_event_sysref_alignment_error
+  input core_event_sysref_alignment_error,
+  input core_event_sysref_edge
 );
 
 reg up_status_sysref_alignment_error = 1'b0;
 wire up_status_sysref_captured;
 
+reg [1:0] up_sysref_status;
+reg [1:0] up_sysref_status_clear;
+wire [1:0] up_sysref_event;
+
+sync_event #(
+  .NUM_OF_EVENTS(2)
+) i_sysref_event_sync (
+  .in_clk(core_clk),
+  .in_event({
+    core_event_sysref_alignment_error,
+    core_event_sysref_edge
+  }),
+  .out_clk(up_clk),
+  .out_event(up_sysref_event)
+);
+
+always @(posedge up_clk) begin
+  if (up_reset == 1'b1) begin
+    up_sysref_status <= 2'b00;
+  end else begin
+    up_sysref_status <= (up_sysref_status & ~up_sysref_status_clear) | up_sysref_event;
+  end
+end
+
 always @(*) begin
   case (up_raddr)
   /* JESD SYSREF configuraton */
@@ -80,6 +105,10 @@ always @(*) begin
     /* 02-09 */ up_cfg_lmfc_offset,
     /* 00-01 */ 2'b00 /* data path alignment for cfg_lmfc_offset */
   };
+  12'h042: up_rdata <= {
+    /* 02-31 */ 30'h00,
+    /* 00-01 */ up_sysref_status
+  };
   default: up_rdata <= 32'h00000000;
   endcase
 end
@@ -104,4 +133,12 @@ always @(posedge up_clk) begin
   end
 end
 
+always @(*) begin
+  if (up_wreq == 1'b1 && up_waddr == 12'h042) begin
+    up_sysref_status_clear <= up_wdata[1:0];
+  end else begin
+    up_sysref_status_clear <= 2'b00;
+  end
+end
+
 endmodule

library/jesd204/axi_jesd204_rx/axi_jesd204_rx.v

@@ -215,7 +215,8 @@ jesd204_up_sysref i_up_sysref (
   .up_reset(up_reset),
 
   .core_clk(core_clk),
-  .core_event_sysref_alignment_error(),
+  .core_event_sysref_edge(core_event_sysref_edge),
+  .core_event_sysref_alignment_error(core_event_sysref_alignment_error),
 
   .up_raddr(up_raddr),
   .up_rdata(up_rdata_sysref),

library/jesd204/axi_jesd204_rx/axi_jesd204_rx_constr.xdc

@@ -63,6 +63,18 @@ set_false_path \
   -from [get_pins {i_up_rx/i_sync_status/out_toggle_d1_reg/C}] \
   -to [get_pins {i_up_rx/i_sync_status/i_sync_in/cdc_sync_stage1_reg[0]/D}]
 
+set_false_path \
+  -from [get_pins {i_up_sysref/i_sysref_event_sync/in_toggle_d1_reg/C}] \
+  -to [get_pins {i_up_sysref/i_sysref_event_sync/i_sync_out/cdc_sync_stage1_reg[0]/D}]
+
+set_false_path \
+  -from [get_pins {i_up_sysref/i_sysref_event_sync/out_toggle_d1_reg/C}] \
+  -to [get_pins {i_up_sysref/i_sysref_event_sync/i_sync_in/cdc_sync_stage1_reg[0]/D}]
+
+set_false_path \
+  -from [get_pins {i_up_sysref/i_sysref_event_sync/cdc_hold_reg*/C}] \
+  -to [get_pins {i_up_sysref/i_sysref_event_sync/out_event_reg*/D}]
+
 # Don't place them too far appart
 set_max_delay -datapath_only \
   -from [get_pins {i_up_rx/i_sync_status/cdc_hold_reg[*]/C}] \

library/jesd204/axi_jesd204_tx/axi_jesd204_tx.v

@@ -240,7 +240,8 @@ jesd204_up_sysref i_up_sysref (
   .up_reset(up_reset),
 
   .core_clk(core_clk),
-  .core_event_sysref_alignment_error(1'b0), // FIXME
+  .core_event_sysref_alignment_error(core_event_sysref_alignment_error),
+  .core_event_sysref_edge(core_event_sysref_edge),
 
   .up_cfg_lmfc_offset(up_cfg_lmfc_offset),
   .up_cfg_sysref_oneshot(up_cfg_sysref_oneshot),

library/jesd204/axi_jesd204_tx/axi_jesd204_tx_constr.xdc

@@ -63,6 +63,18 @@ set_false_path \
   -from [get_pins {i_up_tx/i_sync_state/in_toggle_d1_reg/C}] \
   -to [get_pins {i_up_tx/i_sync_state/i_sync_out/cdc_sync_stage1_reg[0]/D}]
 
+set_false_path \
+  -from [get_pins {i_up_sysref/i_sysref_event_sync/in_toggle_d1_reg/C}] \
+  -to [get_pins {i_up_sysref/i_sysref_event_sync/i_sync_out/cdc_sync_stage1_reg[0]/D}]
+
+set_false_path \
+  -from [get_pins {i_up_sysref/i_sysref_event_sync/out_toggle_d1_reg/C}] \
+  -to [get_pins {i_up_sysref/i_sysref_event_sync/i_sync_in/cdc_sync_stage1_reg[0]/D}]
+
+set_false_path \
+  -from [get_pins {i_up_sysref/i_sysref_event_sync/cdc_hold_reg*/C}] \
+  -to [get_pins {i_up_sysref/i_sysref_event_sync/out_event_reg*/D}]
+
 # Don't place them too far appart
 set_max_delay -datapath_only \
   -from [get_pins {i_up_tx/i_sync_state/cdc_hold_reg[*]/C}] \

library/jesd204/jesd204_common/lmfc.v

@@ -51,14 +51,12 @@ module jesd204_lmfc (
   input [7:0] cfg_beats_per_multiframe,
   input [7:0] cfg_lmfc_offset,
   input cfg_sysref_oneshot,
-  input clear_sysref_captured,
   input cfg_sysref_disable,
 
   output reg lmfc_edge,
   output reg lmfc_clk,
   output reg [7:0] lmfc_counter,
 
-  output reg sysref_captured,
   output reg sysref_edge,
   output reg sysref_alignment_error
 );
@@ -68,6 +66,8 @@ reg sysref_d1 = 1'b0;
 reg sysref_d2 = 1'b0;
 reg sysref_d3 = 1'b0;
 
+reg sysref_captured;
+
 /* lmfc_octet_counter = lmfc_counter * (char_clock_rate / device_clock_rate) */
 reg [7:0] lmfc_counter_next = 'h00;
 
@@ -104,8 +104,6 @@ always @(posedge clk) begin
     sysref_captured <= 1'b0;
   end else if (sysref_edge == 1'b1) begin
     sysref_captured <= 1'b1;
-  end else if (clear_sysref_captured == 1'b1) begin
-    sysref_captured <= 1'b0;
   end
 end
 

library/jesd204/jesd204_rx/rx.v

@@ -221,10 +221,7 @@ jesd204_lmfc i_lmfc (
   .lmfc_counter(lmfc_counter),
 
   .sysref_edge(event_sysref_edge),
-  .sysref_alignment_error(event_sysref_alignment_error),
+  .sysref_alignment_error(event_sysref_alignment_error)
-
-  .sysref_captured(),
-  .clear_sysref_captured(1'b0)
 );
 
 jesd204_rx_ctrl #(

library/jesd204/jesd204_tx/tx.v

@@ -127,8 +127,6 @@ jesd204_lmfc i_lmfc (
 
   .sysref(sysref),
 
-  .clear_sysref_captured(1'b0),
-  .sysref_captured(),
   .sysref_edge(event_sysref_edge),
   .sysref_alignment_error(event_sysref_alignment_error),