From 4f03acd07d5239f496ee6c95f899976e9acf53f1 Mon Sep 17 00:00:00 2001
From: Eric Kooistra <kooistra@astron.nl>
Date: Thu, 1 Dec 2022 16:42:23 +0100
Subject: [PATCH] Correct c_diag_bg_gapsize_w to 31 bit to fit NATURAL range.

---
 libraries/base/diag/src/vhdl/diag_pkg.vhd | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libraries/base/diag/src/vhdl/diag_pkg.vhd b/libraries/base/diag/src/vhdl/diag_pkg.vhd
index 474fa26827..9758197ca6 100644
--- a/libraries/base/diag/src/vhdl/diag_pkg.vhd
+++ b/libraries/base/diag/src/vhdl/diag_pkg.vhd
@@ -106,10 +106,12 @@ PACKAGE diag_pkg IS
   CONSTANT c_diag_bg_reg_adr_w    : NATURAL := ceil_log2(c_diag_bg_reg_nof_dat);
   CONSTANT c_diag_bg_reg_adr_span : NATURAL := 2**c_diag_bg_reg_adr_w;
 
+  -- Use c_diag_bg_gapsize_w = 31 to fit gapsize in 31 bit NATURAL. At 200 MHz
+  -- clock this allows a gap of 2**31 / 200e6 = 10.7 s
   CONSTANT c_diag_bg_mode_w               : NATURAL :=  8;
   CONSTANT c_diag_bg_samples_per_packet_w : NATURAL := 24;   
   CONSTANT c_diag_bg_blocks_per_sync_w    : NATURAL := 24;   
-  CONSTANT c_diag_bg_gapsize_w            : NATURAL := 32;
+  CONSTANT c_diag_bg_gapsize_w            : NATURAL := 31;
   CONSTANT c_diag_bg_mem_adrs_w           : NATURAL := 24;  
   CONSTANT c_diag_bg_mem_low_adrs_w       : NATURAL := c_diag_bg_mem_adrs_w;  
   CONSTANT c_diag_bg_mem_high_adrs_w      : NATURAL := c_diag_bg_mem_adrs_w;
-- 
GitLab