Add test uart_loopback

verilog/dv/cocotb/tests.json

@@ -186,7 +186,12 @@
             "GL":["r_gl","nightly","weekly","tape_out"],
             "GL_SDF":["r_sdf","weekly","tape_out"],
             "description":"test uart reception"}
-
+        ,"uart_loopback" :{"level":0, 
+            "SW":true,
+            "RTL":["r_rtl","setup","nightly","weekly","tape_out"],
+            "GL":["r_gl","nightly","weekly","tape_out"],
+            "GL_SDF":["r_sdf","weekly","tape_out"],
+            "description":"test uart in loopback mode input and output is shorted"}
         ,"spi_master_rd" :{"level":0, 
             "SW":true,
             "RTL":["r_rtl","setup","nightly","weekly","tape_out"],

verilog/dv/cocotb/tests/uart/uart.py

@@ -1,7 +1,7 @@
 from curses import baudrate
 import random
 import cocotb
-from cocotb.triggers import FallingEdge,RisingEdge,ClockCycles,Timer
+from cocotb.triggers import FallingEdge,RisingEdge,ClockCycles,Timer,Edge
 import cocotb.log
 from cpu import RiskV
 from defsParser import Regs
@@ -72,7 +72,6 @@ async def uart_rx(dut):
     clk = clock.period/1000
     global bit_time_ns
     bit_time_ns = round(10**5 * clk / (96))
-    print (clk)
     # send first char
     await wait_reg1(cpu,caravelEnv,0XAA)  
     await uart_send_char(caravelEnv,"B")
@@ -123,4 +122,43 @@ async def uart_check_char_recieved(caravelEnv,cpu):
             cocotb.log.error(f"[TEST] Failed cpu has recieved the wrong character {chr(int(reg_uart_data,2))}")  
             return
                
+        await ClockCycles(caravelEnv.clk,1) 
+
+@cocotb.test()
+@repot_test
+async def uart_loopback(dut):
+    caravelEnv,clock = await test_configure(dut,timeout_cycles=216756)
+    cpu = RiskV(dut)
+    cpu.cpu_force_reset()
+    cpu.cpu_release_reset()
+    cocotb.log.info(f"[TEST] Start uart test")  
+    await cocotb.start( connect_5_6(dut,caravelEnv)) # short gpio 6 and 5
+    caravelEnv.drive_gpio_in((0,0),0) # IO[0] affects the uart selecting btw system and debug
+
+    # setup watcher loopback results 
+    await cocotb.start(uart_check_char_recieved_loopback(caravelEnv,cpu))
+
+    await ClockCycles(caravelEnv.clk,197000) 
+
+async def connect_5_6(dut,caravelEnv):
+    while True:
+        caravelEnv.drive_gpio_in(5,dut.bin6_monitor.value)
+        await Edge(dut.bin6_monitor)
+
+        
+async def uart_check_char_recieved_loopback(caravelEnv,cpu):
+ # check cpu recieved the correct character
+    while True: 
+        reg_uart_data = caravelEnv.caravel_hdl.soc.core.uart_rxtx_w.value.binstr
+        reg1 = cpu.read_debug_reg1()
+        cocotb.log.debug(f"[TEST] reg1 = {hex(reg1)}")   
+        if  reg1 == 0x1B:
+            cocotb.log.info(f"[TEST] Pass cpu has sent and recieved the correct character {chr(int(reg_uart_data,2))}") 
+            await wait_reg1(cpu,caravelEnv,0)   
+            
+        if reg1 == 0x1E:
+            cocotb.log.error(f"[TEST] Failed cpu has sent and recieved the wrong character {chr(int(reg_uart_data,2))}")  
+            await wait_reg1(cpu,caravelEnv,0)   
+            
+               
         await ClockCycles(caravelEnv.clk,1) 

verilog/dv/cocotb/tests/uart/uart_loopback.c

@@ -0,0 +1,64 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Efabless Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <defs.h>
+#include <stub.c>
+#include <uart.h>
+// --------------------------------------------------------
+
+void wait_for_char(char *c){
+    while (uart_rxempty_read() == 1);
+    if (reg_uart_data == *c){
+        reg_debug_1 = 0x1B; // recieved the correct character
+    }else{
+        reg_debug_1 = 0x1E; // timeout didn't recieve the character
+    }
+    reg_debug_1 =0;
+    uart_ev_pending_write(UART_EV_RX);
+}
+
+void main(){
+    int j;
+    reg_wb_enable =1; // for enable writing to reg_debug_1 and reg_debug_2
+    reg_debug_1  = 0x0;
+    reg_debug_2  = 0x0;
+
+    reg_mprj_io_6 = GPIO_MODE_MGMT_STD_OUTPUT;
+    reg_mprj_io_5 = GPIO_MODE_MGMT_STD_INPUT_NOPULL;
+
+    // Now, apply the configuration
+    reg_mprj_xfer = 1;
+    while (reg_mprj_xfer == 1);
+
+    reg_uart_enable = 1;
+
+    print("M");
+    wait_for_char("M");
+    
+    print("B");
+    wait_for_char("B");
+
+    print("A");
+    wait_for_char("A");
+
+    print("5");
+    wait_for_char("5");
+
+    print("o");
+    wait_for_char("o");
+
+}