diff --git a/hw/ip/spi_device/rtl/spi_device.sv b/hw/ip/spi_device/rtl/spi_device.sv
index 6a38e6f..291305f 100644
--- a/hw/ip/spi_device/rtl/spi_device.sv
+++ b/hw/ip/spi_device/rtl/spi_device.sv
@@ -281,11 +281,14 @@
   // Interrupts in Flash mode
   logic intr_upload_cmdfifo_not_empty, intr_upload_payload_not_empty;
   logic intr_readbuf_watermark, intr_readbuf_flip;
+  logic flash_sck_readbuf_watermark, flash_sck_readbuf_flip;
 
   // TODO: Implement
-  assign intr_readbuf_watermark        = 1'b 0;
   assign intr_readbuf_flip             = 1'b 0;
 
+  logic  unused_flip_event;
+  assign unused_flip_event = flash_sck_readbuf_flip;
+
   // TPM ===============================================================
   localparam int unsigned TpmFifoDepth    = 4; // 4B
   localparam int unsigned TpmFifoPtrW     = $clog2(TpmFifoDepth+1);
@@ -587,6 +590,14 @@
     .intr_o                 (intr_upload_payload_not_empty_o              )
   );
 
+  prim_pulse_sync u_flash_readbuf_watermark_pulse_sync (
+    .clk_src_i   (clk_spi_in_buf             ),
+    .rst_src_ni  (rst_ni                     ),
+    .src_pulse_i (flash_sck_readbuf_watermark),
+    .clk_dst_i   (clk_i                      ),
+    .rst_dst_ni  (rst_ni                     ),
+    .dst_pulse_o (intr_readbuf_watermark     )
+  );
   prim_intr_hw #(.Width(1)) u_intr_readbuf_watermark (
     .clk_i,
     .rst_ni,
@@ -1229,7 +1240,8 @@
 
     .io_mode_o (sub_iomode [IoModeReadCmd]),
 
-    .read_watermark_o ()
+    .sck_read_watermark_o (flash_sck_readbuf_watermark),
+    .sck_read_flip_o      (flash_sck_readbuf_flip)
   );
 
   // Begin: Read Status ==============================================
diff --git a/hw/ip/spi_device/rtl/spi_readcmd.sv b/hw/ip/spi_device/rtl/spi_readcmd.sv
index a2cb57a..9628b57 100644
--- a/hw/ip/spi_device/rtl/spi_readcmd.sv
+++ b/hw/ip/spi_device/rtl/spi_readcmd.sv
@@ -169,8 +169,12 @@
   output io_mode_e io_mode_o,
 
   // Read watermark event occurs when current address exceeds the threshold cfg
-  // value for the first time after hit the current read buffer (1kB granularity).
-  output read_watermark_o
+  // value for the first time after hit the current read buffer (1kB
+  // granularity).
+  //
+  // These signals are pulse signals.
+  output logic sck_read_watermark_o,
+  output logic sck_read_flip_o
 
 );
 
@@ -332,6 +336,9 @@
   // Indication of data output phase
   logic output_start;
 
+  // Events: watermark, flip
+  logic read_watermark, read_flip;
+
   //////////////
   // Datapath //
   //////////////
@@ -669,6 +676,21 @@
   end
   //- END:   Main state machine -----------------------------------------------
 
+  // Events: register
+  // watermark, flip are pulse signals. watermark pulse width is 1 SCK. flip
+  // pulse width varies (2 to 32).
+  // They are not registered (output of comb logic). Register the signal then
+  // pulse sync at TOP
+  always_ff @(posedge clk_i or negedge sys_rst_ni) begin
+    if (!sys_rst_ni) begin
+      sck_read_watermark_o <= 1'b 0;
+      sck_read_flip_o      <= 1'b 0;
+    end else begin
+      sck_read_watermark_o <= read_watermark;
+      sck_read_flip_o      <= read_flip;
+    end
+  end
+
   ///////////////
   // Instances //
   ///////////////
@@ -719,8 +741,8 @@
 
     .start_i (output_start),
 
-    .event_watermark_o (read_watermark_o),
-    .event_flip_o      ()
+    .event_watermark_o (read_watermark),
+    .event_flip_o      (read_flip)
   );
 
   ////////////////
diff --git a/hw/ip/spi_device/rtl/spid_readbuffer.sv b/hw/ip/spi_device/rtl/spid_readbuffer.sv
index 51e62f0..3f9e886 100644
--- a/hw/ip/spi_device/rtl/spid_readbuffer.sv
+++ b/hw/ip/spi_device/rtl/spid_readbuffer.sv
@@ -114,6 +114,7 @@
   assign current_buffer_idx = current_address_i[31:OneBufferAw];
   assign flip = current_buffer_idx == next_buffer_addr;
 
+  // TODO: Make event_flip_o pulse signal
   assign event_flip_o = active && flip;
 
   // TODO: Consider the case if host jumps the address? (report error?)