Connect to the caravel logic analyzer

This connects 32 read and 32 write bits to the caravel logic analyzer.

Thanks to Jordan for the original patch

Makefile

@@ -52,7 +52,7 @@ core_files = decode_types.vhdl common.vhdl wishbone_types.vhdl fetch1.vhdl \
 
 soc_files = $(core_files) wishbone_arbiter.vhdl wishbone_bram_wrapper.vhdl sync_fifo.vhdl \
 	wishbone_debug_master.vhdl xics.vhdl syscon.vhdl soc.vhdl \
-	spi_rxtx.vhdl spi_flash_ctrl.vhdl
+	spi_rxtx.vhdl spi_flash_ctrl.vhdl logic_analyzer.vhdl
 
 uart_files = $(wildcard uart16550/*.v)
 

fpga/top-caravel.vhdl

@@ -21,7 +21,9 @@ entity toplevel is
         LOG_LENGTH         : natural := 0;
         UART_IS_16550      : boolean := true;
         HAS_UART1          : boolean := false;
-        HAS_JTAG           : boolean := true
+        HAS_JTAG           : boolean := true;
+        INPUT_IOS  : integer range 0 to 32 := 32;
+        OUTPUT_IOS : integer range 0 to 32 := 32
         );
     port(
         ext_clk   : in  std_ulogic;
@@ -57,11 +59,12 @@ entity toplevel is
 	ib_data        : in  std_ulogic_vector(7 downto 0);
 	ib_pty         : in  std_ulogic;
 
-	-- Add an I/O pin to select fetching from flash on reset
-	alt_reset      : in std_ulogic;
+        -- IO Signals
+        gpio_out : out std_ulogic_vector(OUTPUT_IOS-1 downto 0);
+        gpio_in : in  std_ulogic_vector(INPUT_IOS-1 downto 0);
 
-        -- unused
-        wb_ext_io_out  : out wb_io_slave_out
+	-- Add an I/O pin to select fetching from flash on reset
+	alt_reset      : in std_ulogic
         );
 end entity toplevel;
 
@@ -83,13 +86,18 @@ architecture behaviour of toplevel is
     signal wb_mc_dat_i : wishbone_data_type;
     signal wb_mc_ack   : std_ulogic;
     signal wb_mc_stall : std_ulogic;
+
+    signal wb_logic_analyzer_out    : wb_io_slave_out := wb_io_slave_out_init;
+    signal wb_logic_analyzer_in    : wb_io_master_out;
+
+    signal wb_ext_io_in        : wb_io_master_out;
+    signal wb_ext_io_out       : wb_io_slave_out;
+    signal wb_ext_is_eth       : std_ulogic;
+
 begin
 
     system_rst <= not ext_rst when RESET_LOW else ext_rst;
 
-    -- Unused, but tie it off
-    wb_ext_io_out <= wb_io_slave_out_init;
-
     -- Main SoC
     soc0: entity work.soc
         generic map(
@@ -110,7 +118,8 @@ begin
             LOG_LENGTH         => LOG_LENGTH,
             UART0_IS_16550     => UART_IS_16550,
             HAS_UART1          => HAS_UART1,
-            HAS_JTAG           => HAS_JTAG
+            HAS_JTAG           => HAS_JTAG,
+            HAS_LITEETH        => true
             )
         port map (
             -- System signals
@@ -143,6 +152,10 @@ begin
             wb_dram_in           => wb_dram_out,
             wb_dram_out          => wb_dram_in,
 
+            wb_ext_io_in         => wb_ext_io_in,
+            wb_ext_io_out        => wb_ext_io_out,
+            wb_ext_is_eth        => wb_ext_is_eth,
+
 	    -- Reset PC to flash offset 0 (ie 0xf000000)
 	    alt_reset            => alt_reset
             );
@@ -180,6 +193,30 @@ begin
 --	    int          => ob int
     );
 
+    logic_analyzer: entity work.logic_analyzer
+        generic map(
+            INPUT_IOS  => INPUT_IOS,
+            OUTPUT_IOS  => OUTPUT_IOS
+            )
+        port map(
+            clk => ext_clk,
+            rst => system_rst,
+	    wb_in => wb_logic_analyzer_in,
+	    wb_out => wb_logic_analyzer_out,
+            io_in => gpio_in,
+            io_out => gpio_out
+        );
+
+	wb_logic_analyzer_in.adr <= wb_ext_io_in.adr;
+	wb_logic_analyzer_in.dat <= wb_ext_io_in.dat;
+	wb_logic_analyzer_in.cyc <= wb_ext_io_in.cyc and wb_ext_is_eth;
+	wb_logic_analyzer_in.stb <= wb_ext_io_in.stb;
+	wb_logic_analyzer_in.sel <= wb_ext_io_in.sel;
+	wb_logic_analyzer_in.we <= wb_ext_io_in.we;
+
+        wb_ext_io_out <= wb_logic_analyzer_out;
+
+
     -- External bus wishbone
     wb_mc_adr      <= wb_dram_out.adr;
     wb_mc_dat_o    <= wb_dram_out.dat;

logic_analyzer.vhdl

@@ -0,0 +1,53 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+library work;
+use work.common.all;
+use work.wishbone_types.all;
+
+entity logic_analyzer is
+    generic (
+        INPUT_IOS  : integer range 0 to 32;
+        OUTPUT_IOS : integer range 0 to 32
+        );
+    port (
+        clk     : in std_ulogic;
+        rst     : in std_ulogic;
+        wb_in   : in wb_io_master_out;
+        wb_out  : out wb_io_slave_out;
+        io_in   : in std_ulogic_vector(INPUT_IOS-1 downto 0);
+        io_out  : out std_ulogic_vector(OUTPUT_IOS-1 downto 0)
+      );
+end logic_analyzer;
+
+architecture rtl of logic_analyzer is
+    signal we: std_ulogic;
+    signal re: std_ulogic;
+    signal ack: std_ulogic;
+begin
+    -- Wishbone interface
+    we <= wb_in.stb and wb_in.cyc and wb_in.we;
+    re <= wb_in.stb and wb_in.cyc and not wb_in.we;
+    wb_out.stall <= '0';
+    wb_out.ack <= ack;
+
+    wb_0: process(clk)
+    begin
+        if rising_edge(clk) then
+            if rst = '1' then
+                io_out <= (others => '0');
+                ack <= '0';
+            else
+		if re = '1' then
+                    wb_out.dat(INPUT_IOS-1 downto 0) <= io_in;
+                    ack <= '1';
+	        elsif  we = '1' then
+                    io_out <= wb_in.dat(INPUT_IOS-1 downto 0);
+                    ack <= '1';
+		else
+                    ack <= '0';
+                end if;
+            end if;
+        end if;
+    end process;
+end architecture rtl;

soc.vhdl

@@ -30,6 +30,7 @@ use work.wishbone_types.all;
 
 -- External IO bus:
 -- 0xc8000000: LiteDRAM control (CSRs)
+-- We will put the gpios here ... 
 -- 0xc8020000: LiteEth CSRs (*)
 -- 0xc8030000: LiteEth MMIO (*)