Found and squashed a nasty bug where the WB bus could stall.

The problem was that the WR core did not expose the err and rty lines. If a device ever used these lines (the crossbar does for example), then the master would get hung waiting for an answer.

Found and squashed a nasty bug where the WB bus could stall.
The problem was that the WR core did not expose the err and rty lines. If a device ever used these lines (the crossbar does for example), then the master would get hung waiting for an answer.
cd879ba4 · Wesley W. Terpstra · 53045de6 · cd879ba4 · cd879ba4
Commit cd879ba4 authored May 08, 2012 by Wesley W. Terpstra
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Showing with 8 additions and 2 deletions

wr_core.vhd modules/wrc_core/wr_core.vhd +4 -0

xwr_core.vhd modules/wrc_core/xwr_core.vhd +4 -2

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--- a/modules/wrc_core/wr_core.vhd
+++ b/modules/wrc_core/wr_core.vhd
@@ -165,6 +165,8 @@ entity wr_core is
    wb_cyc_i   : in  std_logic                                               := '0';
    wb_stb_i   : in  std_logic                                               := '0';
    wb_ack_o   : out std_logic;
+    wb_err_o   : out std_logic;
+    wb_rty_o   : out std_logic;
    wb_stall_o : out std_logic;

    -----------------------------------------
@@ -724,6 +726,8 @@ begin
      sl_we_i    => wb_we_i,
      sl_dat_o   => wb_dat_o,
      sl_ack_o   => wb_ack_o,
+      sl_err_o   => wb_err_o,
+      sl_rty_o   => wb_rty_o,
      sl_stall_o => wb_stall_o);

  -----------------------------------------------------------------------------

--- a/modules/wrc_core/xwr_core.vhd
+++ b/modules/wrc_core/xwr_core.vhd
@@ -253,6 +253,8 @@ architecture struct of xwr_core is
      wb_cyc_i   : in  std_logic;
      wb_stb_i   : in  std_logic;
      wb_ack_o   : out std_logic;
+      wb_err_o   : out std_logic;
+      wb_rty_o   : out std_logic;
      wb_stall_o : out std_logic;

      ext_snk_adr_i   : in  std_logic_vector(1 downto 0)  := "00";
@@ -367,6 +369,8 @@ begin
      wb_cyc_i   => slave_i.cyc,
      wb_stb_i   => slave_i.stb,
      wb_ack_o   => slave_o.ack,
+      wb_err_o   => slave_o.err,
+      wb_rty_o   => slave_o.rty,
      wb_stall_o => slave_o.stall,

      ext_snk_adr_i   => wrf_snk_i.adr,
@@ -414,8 +418,6 @@ begin

  timestamps_o.port_id(5) <= '0';

-  slave_o.err <= '0';
-  slave_o.rty <= '0';
  slave_o.int <= '0';

  wrf_snk_o.rty <= '0';