autoapproach: add reset test to bram

firmware/rtl/autoapproach/autoapproach.v

@@ -6,7 +6,8 @@
 module autoapproach #(
 	parameter DAC_WID = 24,
 	parameter DAC_DATA_WID = 20,
-	parameter ADC_WID = 24
+	parameter ADC_WID = 24,
+	parameter TIMER_WID = 32
 ) (
 	input clk,
 	input arm,
@@ -15,6 +16,7 @@ module autoapproach #(
 
 	input polarity,
 	input [ADC_WID-1:0] setpoint,
+	input [TIMER_WID-1:0] time_to_wait,
 
 	/* BRAM memory interface. Each pulse returns the next value in
 	 * the sequence, and also informs the module if the sequence
@@ -39,21 +41,32 @@ module autoapproach #(
 
 
 localparam WAIT_ON_ARM = 0;
-localparam RECV_WORD = 1;
-localparam WAIT_ON_DAC = 2;
-localparam WAIT_ON_DETECTION = 3;
-localparam DETECTED = 4;
+localparam DO_WAIT = 1;
+localparam RECV_WORD = 2;
+localparam WAIT_ON_DAC = 3;
+localparam WAIT_ON_DETECTION = 4;
+localparam DETECTED = 5;
 reg [2:0] state = WAIT_ON_ARM;
 
+reg [TIMER_WID-1:0] wait_timer = 0;
+
 always @ (posedge clk) case (state)
 WAIT_ON_ARM: if (arm) begin
-	state <= RECV_WORD;
-	word_next <= 1;
+	state <= DO_WAIT;
 	stopped <= 0;
+	wait_timer <= time_to_wait;
 end else begin
 	stopped <= 1;
 	word_rst <= 1;
 end
+DO_WAIT: if (!arm) begin
+	state <= WAIT_ON_ARM;
+end else if (wait_timer == 0) begin
+	word_next <= 1;
+	state <= RECV_WORD;
+end else begin
+	wait_timer <= wait_timer - 1;
+end
 RECV_WORD: if (word_ok) begin
 	dac_out <= {4'b0001, word};
 	dac_arm <= 1;

firmware/rtl/autoapproach/bram_interface.v

@@ -86,6 +86,9 @@ reg [WORD_AMNT_WID-1:0] auto_cntr = 0;
 
 always @ (posedge clk) if (word_rst) begin
 	auto_cntr <= 0;
+	word_ok <= 0;
+	word_last <= 0;
+	word <= 0;
 end else if (word_next && !word_ok) begin
 	if (refresh_state == WAIT_ON_REFRESH) begin
 		word <= backing_buffer[auto_cntr];

firmware/rtl/autoapproach/bram_interface_sim.cpp

@@ -86,6 +86,24 @@ static void test_aa_read_1() {
 	my_assert(ind == WORD_AMNT, "second read value %zu != %d\n", ind, WORD_AMNT);
 }
 
+static void test_aa_read_interrupted() {
+	size_t ind = 0;
+
+	mod->word_next = 1;
+	run_clock();
+	for (int i = 0; i < 100; i++) {
+		handle_read_aa(ind);
+		run_clock();
+		my_assert(!mod->word_last, "too many reads");
+	}
+	mod->word_rst = 1;
+	run_clock();
+	mod->word_rst = 0;
+	run_clock();
+
+	test_aa_read_1();
+}
+
 static void refresh_data() {
 	for (size_t i = 0; i < RAM_WID; i++) {
 		ram_refresh_data[i] = mask_extend(rand(), 20);
@@ -108,10 +126,15 @@ static void refresh_data() {
 int main(int argc, char **argv) {
 	init(argc, argv);
 
+	printf("test basic read/write\n");
 	refresh_data();
 	test_aa_read_1();
 	refresh_data();
 	test_aa_read_1();
+
+	printf("test resetting\n");
+	test_aa_read_interrupted();
+
 	printf("ok\n");
 
 	return 0;