verilog/dv/modbus_test/modbus_test.c

/*
 * 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
 */

// This include is relative to $CARAVEL_PATH (see Makefile)
#include <defs.h>
#include <stub.c>

/*
	Wishbone Test:
		- Configures MPRJ lower 8-IO pins as outputs
		- Checks counter value through the wishbone port
*/

void main()
{

	/* 
	IO Control Registers
	| DM     | VTRIP | SLOW  | AN_POL | AN_SEL | AN_EN | MOD_SEL | INP_DIS | HOLDH | OEB_N | MGMT_EN |
	| 3-bits | 1-bit | 1-bit | 1-bit  | 1-bit  | 1-bit | 1-bit   | 1-bit   | 1-bit | 1-bit | 1-bit   |
	Output: 0000_0110_0000_1110  (0x1808) = GPIO_MODE_USER_STD_OUTPUT
	| DM     | VTRIP | SLOW  | AN_POL | AN_SEL | AN_EN | MOD_SEL | INP_DIS | HOLDH | OEB_N | MGMT_EN |
	| 110    | 0     | 0     | 0      | 0      | 0     | 0       | 1       | 0     | 0     | 0       |
	
	 
	Input: 0000_0001_0000_1111 (0x0402) = GPIO_MODE_USER_STD_INPUT_NOPULL
	| DM     | VTRIP | SLOW  | AN_POL | AN_SEL | AN_EN | MOD_SEL | INP_DIS | HOLDH | OEB_N | MGMT_EN |
	| 001    | 0     | 0     | 0      | 0      | 0     | 0       | 0       | 0     | 1     | 0       |
	*/

	/* Set up the housekeeping SPI to be connected internally so	*/
	/* that external pin changes don't affect it.			*/

    reg_spi_enable = 1;
    reg_wb_enable = 1;
	// reg_spimaster_config = 0xa002;	// Enable, prescaler = 2,
                                        // connect to housekeeping SPI

	// Connect the housekeeping SPI to the SPI master
	// so that the CSB line is not left floating.  This allows
	// all of the GPIO pins to be used for user functions.

    reg_mprj_io_10  = GPIO_MODE_MGMT_STD_OUTPUT;
    reg_mprj_io_9   = GPIO_MODE_USER_STD_INPUT_NOPULL;
    reg_mprj_io_8   = GPIO_MODE_USER_STD_OUTPUT;

     /* Apply configuration */
    reg_mprj_xfer = 1;
    while (reg_mprj_xfer == 1)

    // Flag start of the test
	reg_mprj_datal = 0x00000400;

    while ((*(volatile uint32_t*)0x30000000) != 0x00000001);

    (*(volatile uint32_t*)0x30000200) = 0x0000596f;
    (*(volatile uint32_t*)0x30000204) = 0x00006e67;
    (*(volatile uint32_t*)0x30000208) = 0x00006174;
    (*(volatile uint32_t*)0x3000020C) = 0x0000656b;

}