Icestick uart (#37)

* added UART example for the icestick

* extended testsuite by the UART example

1 files changed, 49 insertions, 0 deletions

diff --git a/icestick/uart/hdl/uart_top.vhd b/icestick/uart/hdl/uart_top.vhd
new file mode 100755
index 0000000..889a3a0
--- /dev/null
+++ b/icestick/uart/hdl/uart_top.vhd
@@ -0,0 +1,49 @@
+library ieee;
+  use ieee.std_logic_1164.all;
+
+entity uart_top is
+  generic (
+    C_BITS : integer := 8
+  );
+  port (
+    isl_clk    : in std_logic;
+    isl_data_n : in std_logic;
+    osl_data_n : out std_logic;
+    osl_ready  : out std_logic
+  );
+end uart_top;
+
+architecture behavioral of uart_top is
+  constant C_QUARTZ_FREQ : integer := 12000000; -- Hz
+  constant C_BAUDRATE : integer := 115200; -- words / s
+  constant C_CYCLES_PER_BIT : integer := C_QUARTZ_FREQ / C_BAUDRATE;
+
+  signal sl_valid_out_tx : std_logic := '0';
+  signal slv_data_out_tx : std_logic_vector(C_BITS-1 downto 0) := (others => '0');
+
+begin
+  i_uart_rx: entity work.uart_rx
+  generic map (
+    C_BITS => C_BITS,
+    C_CYCLES_PER_BIT => C_CYCLES_PER_BIT
+  )
+  port map (
+    isl_clk => isl_clk,
+    isl_data_n => isl_data_n,
+    oslv_data => slv_data_out_tx,
+    osl_valid => sl_valid_out_tx
+  );
+
+  i_uart_tx: entity work.uart_tx
+  generic map (
+    C_BITS => C_BITS,
+    C_CYCLES_PER_BIT => C_CYCLES_PER_BIT
+  )
+  port map (
+    isl_clk => isl_clk,
+    isl_valid => sl_valid_out_tx,
+    islv_data => slv_data_out_tx,
+    osl_data_n => osl_data_n,
+    osl_ready => osl_ready
+  );
+end behavioral;
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