diff --git a/libraries/dsp/st/src/vhdl/st_histogram_reg.vhd b/libraries/dsp/st/src/vhdl/st_histogram_reg.vhd
index 6887bc5945003241b077a77c59bcd60b1909dba9..9230e11503c35feb7cbe26464f04d10776d48d51 100644
--- a/libraries/dsp/st/src/vhdl/st_histogram_reg.vhd
+++ b/libraries/dsp/st/src/vhdl/st_histogram_reg.vhd
@@ -24,8 +24,7 @@
 -- . Provide MM registers for st_histogram
 -- Description:
 -- . Address 0, bit 0 = RAM clear
---   . Read : 'ram_clearing' status.  '1' right after write of ram_clear. '0' when not clearing RAM (anymore).
---   . Write: 'ram_clear '   control. '1' to clear RAM on write event.
+--   . Read : 'ram_clearing' status output of st_histogram.vhd. '1' when RAM is clearing.
 -- . Address 1 = select RAM instance to fill (read out)
 --   . Read : read back selected instance
 --   . Write: select RAM instance to fill
@@ -47,7 +46,6 @@ ENTITY st_histogram_reg IS
     dp_clk        : IN  STD_LOGIC;
     dp_rst        : IN  STD_LOGIC;
   
-    ram_clear     : OUT STD_LOGIC;
     ram_clearing  : IN  STD_LOGIC;
   
     ram_fill_inst : OUT STD_LOGIC_VECTOR(ceil_log2(g_nof_instances)-1 DOWNTO 0);