Add monitoring of ADC sample and min/max range

fpga/rtl/acquisition_chain.vhd

@@ -54,9 +54,6 @@ entity acquisition_chain is
         -- Ignored if num_channels == 2.
         ch4_mode:           in  std_logic;
 
-        -- High to use simulated samples in place of real ADC samples.
-        simulate_adc:       in  std_logic;
-
         -- High to enable automatic (continuous) triggering.
         trig_auto_en:       in  std_logic;
 
@@ -142,25 +139,6 @@ begin
             sample_integrate => s_sample_integrate,
             sample_done     => s_sample_done );
 
-    -- Optionally generate simulated ADC data.
-    inst_adc_sample_stream: entity work.adc_sample_stream
-        port map (
-            clk                 => clk,
-            reset               => reset,
-            simulate            => simulate_adc,
-            in_data             => adc_data_in(0 to 1),
-            out_data            => s_adc_sample(0 to 1) );
-
-    inst_adc_sample_stream_gen: if num_channels > 2 generate
-        inst_adc_sample_stream2: entity work.adc_sample_stream
-            port map (
-                clk                 => clk,
-                reset               => reset,
-                simulate            => simulate_adc,
-                in_data             => adc_data_in(2 to 3),
-                out_data            => s_adc_sample(2 to 3) );
-    end generate;
-
     -- Shift and decimation chains for each ADC channel.
     inst_channels: for i in 0 to num_channels - 1 generate
 
@@ -172,7 +150,7 @@ begin
                 signed_data     => false )
             port map (
                 clk             => clk,
-                in_data         => s_adc_sample(i),
+                in_data         => adc_data_in(i),
                 in_shift        => shift_steps,
                 out_data        => s_adc_shifted(i) );
 

fpga/rtl/adc_range_monitor.vhd

@@ -0,0 +1,107 @@
+--
+--  Monitor min/max sample values from ADC.
+--
+--  Joris van Rantwijk 2024
+--
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+use work.puzzlefw_pkg.all;
+
+
+entity adc_range_monitor is
+
+    generic (
+        -- True if ADC samples are signed values.
+        -- False if ADC samples are unsigned binary offset values.
+        signed_data:        boolean
+    );
+
+    port (
+        -- Main clock, active on rising edge.
+        clk:                in  std_logic;
+
+        -- Reset, active high, synchronous to main clock.
+        reset:              in  std_logic;
+
+        -- High to clear min/max sample values.
+        clear:              in  std_logic;
+
+        -- Input sample stream.
+        in_data:            in  adc_data_type;
+
+        -- Minimum and maximum sample value observed.
+        min_value:          out adc_data_type;
+        max_value:          out adc_data_type
+    );
+
+end entity;
+
+architecture arch of adc_range_monitor is
+
+    type regs_type is record
+        min_value:          adc_data_type;
+        max_value:          adc_data_type;
+    end record;
+
+    signal r: regs_type;
+    signal rnext: regs_type;
+
+    -- Return True if X is less than Y.
+    function sample_less(x: adc_data_type; y: adc_data_type)
+        return boolean
+    is begin
+        if signed_data then
+            return signed(x) < signed(y);
+        else
+            return unsigned(x) < unsigned(y);
+        end if;
+    end function;
+
+begin
+
+    -- Drive output.
+    min_value <= r.min_value;
+    max_value <= r.max_value;
+
+    --
+    -- Combinatorial process.
+    --
+    process (all) is
+        variable v: regs_type;
+    begin
+        -- Load current register values.
+        v := r;
+
+        -- Update min value.
+        if (reset = '1')
+                or (clear = '1')
+                or sample_less(in_data, r.min_value) then
+            v.min_value := in_data;
+        end if;
+
+        -- Update max value.
+        if (reset = '1')
+                or (clear = '1')
+                or sample_less(r.max_value, in_data) then
+            v.max_value := in_data;
+        end if;
+
+        -- Drive new register values to synchronous process.
+        rnext <= v;
+
+    end process;
+
+    --
+    -- Synchronous process.
+    --
+    process (clk) is
+    begin
+        if rising_edge(clk) then
+            r <= rnext;
+        end if;
+    end process;
+
+end architecture;

fpga/rtl/puzzlefw_pkg.vhd

@@ -67,6 +67,13 @@ package puzzlefw_pkg is
     constant reg_trigger_mode:      natural := 16#000240#;
     constant reg_trigger_delay:     natural := 16#000244#;
     constant reg_trigger_status:    natural := 16#000248#;
+    constant reg_adc_sample:        natural := 16#000280#;
+    constant reg_adc23_sample:      natural := 16#000284#;
+    constant reg_adc_range_clear:   natural := 16#00028c#;
+    constant reg_adc0_minmax:       natural := 16#000290#;
+    constant reg_adc1_minmax:       natural := 16#000294#;
+    constant reg_adc2_minmax:       natural := 16#000298#;
+    constant reg_adc3_minmax:       natural := 16#00029c#;
     constant reg_test_led:          natural := 16#000404#;
     constant reg_test_divider:      natural := 16#000408#;
     constant reg_dma_buf_addr:      natural := 16#100000#;
@@ -75,7 +82,7 @@ package puzzlefw_pkg is
     -- Firmware info word.
     constant fw_api_version:        natural := 1;
     constant fw_version_major:      natural := 0;
-    constant fw_version_minor:      natural := 3;
+    constant fw_version_minor:      natural := 4;
     constant fw_info_word:          std_logic_vector(31 downto 0) :=
         x"4a"
         & std_logic_vector(to_unsigned(fw_api_version, 8))
@@ -116,6 +123,7 @@ package puzzlefw_pkg is
         trig_ext_select:    std_logic_vector(1 downto 0);
         trig_ext_falling:   std_logic;
         trigger_delay:      std_logic_vector(15 downto 0);
+        adc_range_clear:    std_logic;
         dma_buf_addr:       std_logic_vector(31 downto 12);
         dma_buf_size:       std_logic_vector(31 downto 12);
     end record;
@@ -132,6 +140,9 @@ package puzzlefw_pkg is
         acq_addr_ptr:       std_logic_vector(31 downto 3);
         acq_channel_busy:   std_logic;
         trig_waiting:       std_logic;
+        adc_sample:         adc_data_array(0 to 3);
+        adc_min_value:      adc_data_array(0 to 3);
+        adc_max_value:      adc_data_array(0 to 3);
     end record;
 
     constant registers_control_init: registers_control := (
@@ -162,6 +173,7 @@ package puzzlefw_pkg is
         trig_ext_select     => (others => '0'),
         trig_ext_falling    => '0',
         trigger_delay       => (others => '0'),
+        adc_range_clear     => '0',
         dma_buf_addr        => (others => '0'),
         dma_buf_size        => (others => '0')
     );

fpga/rtl/puzzlefw_top.vhd

@@ -146,6 +146,7 @@ architecture arch of puzzlefw_top is
 
     signal s_timestamp:     std_logic_vector(timestamp_bits - 1 downto 0);
     signal s_adc_data:      adc_data_array(0 to 1);
+    signal s_adc_sample:    adc_data_array(0 to 1);
 
     signal s_acq_dma_valid: std_logic;
     signal s_acq_dma_ready: std_logic;
@@ -397,17 +398,44 @@ begin
 
     -- Capture ADC data.
     -- Ignore the 2 LSB bits which are not-connected on the ADC side.
-    inst_adc_capture1: entity work.adc_capture
+    inst_capture_gen: for i in 0 to 1 generate
+        inst_adc_capture: entity work.adc_capture
             port map (
                 clk                 => clk_adc,
-            in_data             => adc_dat_i(0)(15 downto 2),
+                in_data             => adc_dat_i(i)(15 downto 2),
-            out_data            => s_adc_data(0) );
+                out_data            => s_adc_data(i) );
+    end generate;
 
-    inst_adc_capture2: entity work.adc_capture
+    -- Optionally generate simulated ADC samples.
+    inst_adc_sample_stream: entity work.adc_sample_stream
         port map (
             clk                 => clk_adc,
-            in_data             => adc_dat_i(1)(15 downto 2),
+            reset               => s_reset,
-            out_data            => s_adc_data(1) );
+            simulate            => s_reg_control.simulate_adc,
+            in_data             => s_adc_data(0 to 1),
+            out_data            => s_adc_sample(0 to 1) );
+
+    -- Monitor range of ADC samples.
+    inst_monitor_gen: for i in 0 to 1 generate
+        inst_range_monitor: entity work.adc_range_monitor
+            generic map (
+                signed_data         => false )
+            port map (
+                clk                 => clk_adc,
+                reset               => s_reset,
+                clear               => s_reg_control.adc_range_clear,
+                in_data             => s_adc_sample(i),
+                min_value           => s_reg_status.adc_min_value(i),
+                max_value           => s_reg_status.adc_max_value(i) );
+    end generate;
+
+    -- Monitor current ADC sample value.
+    s_reg_status.adc_sample(0 to 1) <= s_adc_sample(0 to 1);
+
+    -- Drive dummy values to not-implemented channels 2, 3.
+    s_reg_status.adc_sample(2 to 3) <= (others => (others => '0'));
+    s_reg_status.adc_min_value(2 to 3) <= (others => (others => '0'));
+    s_reg_status.adc_max_value(2 to 3) <= (others => (others => '0'));
 
     -- Analog acquisition data chain.
     inst_acquisition_chain: entity work.acquisition_chain
@@ -423,14 +451,13 @@ begin
             averaging           => s_reg_control.averaging_en,
             shift_steps         => s_reg_control.shift_steps,
             ch4_mode            => s_reg_control.ch4_mode,
-            simulate_adc        => s_reg_control.simulate_adc,
             trig_auto_en        => s_reg_control.trig_auto_en,
             trig_ext_en         => s_reg_control.trig_ext_en,
             trig_force          => s_reg_control.trig_force,
             trig_ext_select     => s_reg_control.trig_ext_select,
             trig_ext_falling    => s_reg_control.trig_ext_falling,
             timestamp_in        => s_timestamp,
-            adc_data_in         => s_adc_data,
+            adc_data_in         => s_adc_sample,
             trig_ext_in         => "0000",  -- TODO
             trig_waiting        => s_reg_status.trig_waiting,
             out_valid           => s_acq_dma_valid,

fpga/rtl/registers.vhd

@@ -75,6 +75,7 @@ begin
         v.reg_control.acq_channel_init  := '0';
         v.reg_control.acq_intr_clear    := '0';
         v.reg_control.trig_force        := '0';
+        v.reg_control.adc_range_clear   := '0';
 
         -- Respond to each APB access on the next clock cycle (no wait states).
         v.pready        := apb_psel and (not apb_penable);
@@ -122,6 +123,24 @@ begin
                     v.prdata(7) := r.reg_control.trig_ext_falling;
                 when reg_trigger_delay =>   v.prdata(15 downto 0) := r.reg_control.trigger_delay;
                 when reg_trigger_status =>  v.prdata(0) := reg_status.trig_waiting;
+                when reg_adc_sample =>
+                    v.prdata(adc_data_bits - 1 downto 0) := reg_status.adc_sample(0);
+                    v.prdata(adc_data_bits + 15 downto 16) := reg_status.adc_sample(1);
+                when reg_adc23_sample =>
+                    v.prdata(adc_data_bits - 1 downto 0) := reg_status.adc_sample(2);
+                    v.prdata(adc_data_bits + 15 downto 16) := reg_status.adc_sample(3);
+                when reg_adc0_minmax =>
+                    v.prdata(adc_data_bits - 1 downto 0) := reg_status.adc_min_value(0);
+                    v.prdata(adc_data_bits + 15 downto 16) := reg_status.adc_max_value(0);
+                when reg_adc1_minmax =>
+                    v.prdata(adc_data_bits - 1 downto 0) := reg_status.adc_min_value(1);
+                    v.prdata(adc_data_bits + 15 downto 16) := reg_status.adc_max_value(1);
+                when reg_adc2_minmax =>
+                    v.prdata(adc_data_bits - 1 downto 0) := reg_status.adc_min_value(2);
+                    v.prdata(adc_data_bits + 15 downto 16) := reg_status.adc_max_value(2);
+                when reg_adc3_minmax =>
+                    v.prdata(adc_data_bits - 1 downto 0) := reg_status.adc_min_value(3);
+                    v.prdata(adc_data_bits + 15 downto 16) := reg_status.adc_max_value(3);
                 when reg_test_led =>        v.prdata(7 downto 0) := r.reg_control.test_led;
                 when reg_test_divider =>    v.prdata(15 downto 0) := r.reg_control.test_divider;
                 when reg_dma_buf_addr =>    v.prdata(31 downto 12) := r.reg_control.dma_buf_addr;
@@ -162,6 +181,7 @@ begin
                     v.reg_control.trig_ext_falling := apb_pwdata(7);
                     v.reg_control.trig_force := apb_pwdata(8);
                 when reg_trigger_delay =>   v.reg_control.trigger_delay := apb_pwdata(15 downto 0);
+                when reg_adc_range_clear => v.reg_control.adc_range_clear := apb_pwdata(0);
                 when reg_test_led =>        v.reg_control.test_led := apb_pwdata(7 downto 0);
                 when reg_test_divider =>    v.reg_control.test_divider := apb_pwdata(15 downto 0);
                 when reg_dma_buf_addr =>    v.reg_control.dma_buf_addr := apb_pwdata(31 downto 12);

fpga/rtl/trigger_detector.vhd

@@ -52,13 +52,7 @@ architecture arch of trigger_detector is
         trig_out:           std_logic;
     end record;
 
-    constant regs_init: regs_type := (
+    signal r: regs_type;
-        prev_level  => '0',
-        ext_trig        => '0',
-        trig_out        => '0'
-    );
-
-    signal r: regs_type := regs_init;
     signal rnext: regs_type;
 
 begin
@@ -71,7 +65,6 @@ begin
     --
     process (all) is
         variable v: regs_type;
-        variable v_trig: std_logic;
     begin
         -- Load current register values.
         v := r;

fpga/vivado/nonproject.tcl

@@ -23,6 +23,7 @@ read_vhdl -vhdl2008 ../rtl/acquisition_chain.vhd
 read_vhdl -vhdl2008 ../rtl/acquisition_manager.vhd
 read_vhdl -vhdl2008 ../rtl/acquisition_stream.vhd
 read_vhdl -vhdl2008 ../rtl/adc_capture.vhd
+read_vhdl -vhdl2008 ../rtl/adc_range_monitor.vhd
 read_vhdl -vhdl2008 ../rtl/adc_sample_stream.vhd
 read_vhdl -vhdl2008 ../rtl/dma_axi_master.vhd
 read_vhdl -vhdl2008 ../rtl/dma_write_channel.vhd

os/src/userspace/testje.c

@@ -51,6 +51,13 @@
 #define REG_TRIGGER_MODE        0x0240
 #define REG_TRIGGER_DELAY       0x0244
 #define REG_TRIGGER_STATUS      0x0248
+#define REG_ADC_SAMPLE          0x0280
+#define REG_ADC23_SAMPLE        0x0284
+#define REG_ADC_RANGE_CLEAR     0x028c
+#define REG_ADC0_MINMAX         0x0290
+#define REG_ADC1_MINMAX         0x0294
+#define REG_ADC2_MINMAX         0x0298
+#define REG_ADC3_MINMAX         0x029c
 
 
 struct puzzlefw_context {
@@ -601,6 +608,19 @@ static void show_status(struct puzzlefw_context *ctx)
 
     v = puzzlefw_read_reg(ctx, REG_AVERAGING_EN);
     printf("    averaging_en =   0x%08x\n", v);
+
+    v = puzzlefw_read_reg(ctx, REG_ADC_SAMPLE);
+    uint32_t adc_range = puzzlefw_read_reg(ctx, REG_ADC0_MINMAX);
+    printf("    channel 0    =   %5u  (min = %u, max = %u)\n",
+           v & 0xffff,
+           adc_range & 0xffff,
+           (adc_range >> 16) & 0xffff);
+
+    adc_range = puzzlefw_read_reg(ctx, REG_ADC1_MINMAX);
+    printf("    channel 1    =   %5u  (min = %u, max = %u)\n",
+           (v >> 16) & 0xffff,
+           adc_range & 0xffff,
+           (adc_range >> 16) & 0xffff);
 }
 
 
@@ -1037,6 +1057,7 @@ int main(int argc, char **argv)
     int set_shift = 0, shift_steps = 0;
     int avgon = 0, avgoff = 0;
     int simon = 0, simoff = 0;
+    int rangeclear = 0;
 
     if (argc == 2 && strcmp(argv[1], "show") == 0) {
         show = 1;
@@ -1084,6 +1105,8 @@ int main(int argc, char **argv)
         simon = 1;
     } else if (argc == 2 && strcmp(argv[1], "simoff") == 0) {
         simoff = 1;
+    } else if (argc == 2 && strcmp(argv[1], "rangeclear") == 0) {
+        rangeclear = 1;
     } else if (argc == 2 && strcmp(argv[1], "server") == 0) {
         server = 1;
     } else {
@@ -1152,6 +1175,9 @@ int main(int argc, char **argv)
             "    testje simoff\n"
             "        Use real ADC data.\n"
             "\n"
+            "    testje rangeclear\n"
+            "        Clear min/max ADC sample monitor.\n"
+            "\n"
             "    testje server\n"
             "        Open TCP port 5001 to stream DMA data.\n"
             "\n");
@@ -1251,6 +1277,10 @@ int main(int argc, char **argv)
         puzzlefw_write_reg(&ctx, REG_SIMULATE_ADC, 0);
     }
 
+    if (rangeclear) {
+        puzzlefw_write_reg(&ctx, REG_ADC_RANGE_CLEAR, 1);
+    }
+
     if (server) {
         run_server(&ctx);
     }