lss: Use SV enums in low-speed serial logic

Signed-off-by: Alex Forencich <alex@alexforencich.com>

src/lss/rtl/taxi_i2c_init.sv

@@ -189,14 +189,15 @@ initial begin
     init_data[21] = cmd_halt(); // halt
 end
 
-localparam [2:0]
-    STATE_IDLE = 3'd0,
-    STATE_RUN = 3'd1,
-    STATE_TABLE_1 = 3'd2,
-    STATE_TABLE_2 = 3'd3,
-    STATE_TABLE_3 = 3'd4;
+typedef enum logic [2:0] {
+    STATE_IDLE,
+    STATE_RUN,
+    STATE_TABLE_1,
+    STATE_TABLE_2,
+    STATE_TABLE_3
+} state_t;
 
-logic [2:0] state_reg = STATE_IDLE, state_next;
+state_t state_reg = STATE_IDLE, state_next;
 
 localparam AW = $clog2(INIT_DATA_LEN);
 

src/lss/rtl/taxi_i2c_master.sv

@@ -158,41 +158,43 @@ if (s_axis_cmd.DATA_W < 12)
 if (s_axis_tx.DATA_W != 8 || m_axis_rx.DATA_W != 8)
     $fatal(0, "Data interface width must be 8 bits (instance %m)");
 
-localparam [3:0]
-    STATE_IDLE = 4'd0,
-    STATE_ACTIVE_WRITE = 4'd1,
-    STATE_ACTIVE_READ = 4'd2,
-    STATE_START_WAIT = 4'd3,
-    STATE_START = 4'd4,
-    STATE_ADDRESS_1 = 4'd5,
-    STATE_ADDRESS_2 = 4'd6,
-    STATE_WRITE_1 = 4'd7,
-    STATE_WRITE_2 = 4'd8,
-    STATE_WRITE_3 = 4'd9,
-    STATE_READ = 4'd10,
-    STATE_STOP = 4'd11;
+typedef enum logic [3:0] {
+    STATE_IDLE,
+    STATE_ACTIVE_WRITE,
+    STATE_ACTIVE_READ,
+    STATE_START_WAIT,
+    STATE_START,
+    STATE_ADDRESS_1,
+    STATE_ADDRESS_2,
+    STATE_WRITE_1,
+    STATE_WRITE_2,
+    STATE_WRITE_3,
+    STATE_READ,
+    STATE_STOP
+} state_t;
 
-logic [3:0] state_reg = STATE_IDLE, state_next;
+state_t state_reg = STATE_IDLE, state_next;
 
-localparam [3:0]
-    PHY_STATE_IDLE = 4'd0,
-    PHY_STATE_ACTIVE = 4'd1,
-    PHY_STATE_REPEATED_START_1 = 4'd2,
-    PHY_STATE_REPEATED_START_2 = 4'd3,
-    PHY_STATE_START_1 = 4'd4,
-    PHY_STATE_START_2 = 4'd5,
-    PHY_STATE_WRITE_BIT_1 = 4'd6,
-    PHY_STATE_WRITE_BIT_2 = 4'd7,
-    PHY_STATE_WRITE_BIT_3 = 4'd8,
-    PHY_STATE_READ_BIT_1 = 4'd9,
-    PHY_STATE_READ_BIT_2 = 4'd10,
-    PHY_STATE_READ_BIT_3 = 4'd11,
-    PHY_STATE_READ_BIT_4 = 4'd12,
-    PHY_STATE_STOP_1 = 4'd13,
-    PHY_STATE_STOP_2 = 4'd14,
-    PHY_STATE_STOP_3 = 4'd15;
+typedef enum logic [3:0] {
+    PHY_STATE_IDLE,
+    PHY_STATE_ACTIVE,
+    PHY_STATE_REPEATED_START_1,
+    PHY_STATE_REPEATED_START_2,
+    PHY_STATE_START_1,
+    PHY_STATE_START_2,
+    PHY_STATE_WRITE_BIT_1,
+    PHY_STATE_WRITE_BIT_2,
+    PHY_STATE_WRITE_BIT_3,
+    PHY_STATE_READ_BIT_1,
+    PHY_STATE_READ_BIT_2,
+    PHY_STATE_READ_BIT_3,
+    PHY_STATE_READ_BIT_4,
+    PHY_STATE_STOP_1,
+    PHY_STATE_STOP_2,
+    PHY_STATE_STOP_3
+} phy_state_t;
 
-logic [3:0] phy_state_reg = STATE_IDLE, phy_state_next;
+phy_state_t phy_state_reg = PHY_STATE_IDLE, phy_state_next;
 
 logic phy_start_bit;
 logic phy_stop_bit;
@@ -359,7 +361,7 @@ always_comb begin
                         mode_stop_next = s_axis_cmd_stop;
 
                         s_axis_cmd_ready_next = 1'b0;
-                        
+
                         if (s_axis_cmd_start || s_axis_cmd_address != addr_reg || s_axis_cmd_read) begin
                             // address or mode mismatch or forced start - repeated start
 
@@ -406,7 +408,7 @@ always_comb begin
                         mode_stop_next = s_axis_cmd_stop;
 
                         s_axis_cmd_ready_next = 1'b0;
-                        
+
                         if (s_axis_cmd_start || s_axis_cmd_address != addr_reg || s_axis_cmd_write) begin
                             // address or mode mismatch or forced start - repeated start
 

src/lss/rtl/taxi_i2c_single_reg.sv

@@ -39,17 +39,18 @@ module taxi_i2c_single_reg #(
     output wire logic [7:0]  data_out
 );
 
-localparam [2:0]
-    STATE_IDLE = 3'd0,
-    STATE_ADDRESS = 3'd1,
-    STATE_ACK = 3'd2,
-    STATE_WRITE_1 = 3'd3,
-    STATE_WRITE_2 = 3'd4,
-    STATE_READ_1 = 3'd5,
-    STATE_READ_2 = 3'd6,
-    STATE_READ_3 = 3'd7;
+typedef enum logic [2:0] {
+    STATE_IDLE,
+    STATE_ADDRESS,
+    STATE_ACK,
+    STATE_WRITE_1,
+    STATE_WRITE_2,
+    STATE_READ_1,
+    STATE_READ_2,
+    STATE_READ_3
+} state_t;
 
-logic [2:0] state_reg = STATE_IDLE;
+state_t state_reg = STATE_IDLE;
 
 logic [7:0] data_reg = '0;
 logic [7:0] shift_reg = '0;

src/lss/rtl/taxi_i2c_slave.sv

@@ -75,7 +75,7 @@ This module translates I2C read and write operations into AXI stream transfers.
 Bytes written over I2C will be delayed by one byte time so that the last byte
 in a write operation can be accurately marked.  When reading, the module will
 stretch SCL by holding it low until a data byte is presented at the AXI stream
-input.  
+input.
 
 Control:
 
@@ -139,17 +139,18 @@ I/O pin.  This would prevent devices from stretching the clock period.
 if (s_axis_tx.DATA_W != 8 || m_axis_rx.DATA_W != 8)
     $fatal(0, "Data interface width must be 8 bits (instance %m)");
 
-localparam [2:0]
-    STATE_IDLE = 3'd0,
-    STATE_ADDRESS = 3'd1,
-    STATE_ACK = 3'd2,
-    STATE_WRITE_1 = 3'd3,
-    STATE_WRITE_2 = 3'd4,
-    STATE_READ_1 = 3'd5,
-    STATE_READ_2 = 3'd6,
-    STATE_READ_3 = 3'd7;
+typedef enum logic [2:0] {
+    STATE_IDLE,
+    STATE_ADDRESS,
+    STATE_ACK,
+    STATE_WRITE_1,
+    STATE_WRITE_2,
+    STATE_READ_1,
+    STATE_READ_2,
+    STATE_READ_3
+} state_t;
 
-logic [2:0] state_reg = STATE_IDLE, state_next;
+state_t state_reg = STATE_IDLE, state_next;
 
 logic [6:0] addr_reg = '0, addr_next;
 logic [7:0] data_reg = '0, data_next;

src/lss/rtl/taxi_i2c_slave_apb_master.sv

@@ -178,15 +178,16 @@ if (2**$clog2(BYTE_LANES) != BYTE_LANES)
 if (8*2**$clog2(BYTE_SIZE/8) != BYTE_SIZE)
     $fatal(0, "Error: AXI word size must be a power of two multiple of 8 bits (instance %m)");
 
-localparam [2:0]
-    STATE_IDLE = 3'd0,
-    STATE_ADDRESS = 3'd1,
-    STATE_READ_1 = 3'd2,
-    STATE_READ_2 = 3'd3,
-    STATE_WRITE_1 = 3'd4,
-    STATE_WRITE_2 = 3'd5;
+typedef enum logic [2:0] {
+    STATE_IDLE,
+    STATE_ADDRESS,
+    STATE_READ_1,
+    STATE_READ_2,
+    STATE_WRITE_1,
+    STATE_WRITE_2
+} state_t;
 
-logic [2:0] state_reg = STATE_IDLE, state_next;
+state_t state_reg = STATE_IDLE, state_next;
 
 logic [7:0] count_reg = '0, count_next;
 logic last_cycle_reg = 1'b0;

src/lss/rtl/taxi_i2c_slave_axil_master.sv

@@ -181,15 +181,16 @@ if (2**$clog2(BYTE_LANES) != BYTE_LANES)
 if (8*2**$clog2(BYTE_SIZE/8) != BYTE_SIZE)
     $fatal(0, "Error: AXI word size must be a power of two multiple of 8 bits (instance %m)");
 
-localparam [2:0]
-    STATE_IDLE = 3'd0,
-    STATE_ADDRESS = 3'd1,
-    STATE_READ_1 = 3'd2,
-    STATE_READ_2 = 3'd3,
-    STATE_WRITE_1 = 3'd4,
-    STATE_WRITE_2 = 3'd5;
+typedef enum logic [2:0] {
+    STATE_IDLE,
+    STATE_ADDRESS,
+    STATE_READ_1,
+    STATE_READ_2,
+    STATE_WRITE_1,
+    STATE_WRITE_2
+} state_t;
 
-logic [2:0] state_reg = STATE_IDLE, state_next;
+state_t state_reg = STATE_IDLE, state_next;
 
 logic [7:0] count_reg = '0, count_next;
 logic last_cycle_reg = 1'b0;

src/lss/rtl/taxi_mdio_master.sv

@@ -44,12 +44,13 @@ module taxi_mdio_master (
     input  wire logic [7:0]  prescale
 );
 
-localparam [1:0]
-    STATE_IDLE = 2'd0,
-    STATE_PREAMBLE = 2'd1,
-    STATE_TRANSFER = 2'd2;
+typedef enum logic [1:0] {
+    STATE_IDLE,
+    STATE_PREAMBLE,
+    STATE_TRANSFER
+} state_t;
 
-logic [1:0] state_reg = STATE_IDLE, state_next;
+state_t state_reg = STATE_IDLE, state_next;
 
 logic [7:0] count_reg = '0, count_next;
 logic [5:0] bit_count_reg = '0, bit_count_next;