verilog/dv/caravel/user_proj_example/chain/chain.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
 */

#include "../../defs.h"

/*
	SPM Scan-Chain test Test:
*/

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_spimaster_config = 0xa002;	// Enable, prescaler = 2,
                                        // connect to housekeeping SPI

	// Configure JTAG ports
	reg_mprj_io_0 =  GPIO_MODE_USER_STD_INPUT_NOPULL; 	// tck
	reg_mprj_io_1 =  GPIO_MODE_USER_STD_INPUT_NOPULL;   // tms
	reg_mprj_io_2 =  GPIO_MODE_USER_STD_INPUT_NOPULL; 	// tdi
	reg_mprj_io_5 =  GPIO_MODE_USER_STD_INPUT_NOPULL; 	// trst
	reg_mprj_io_4 =  GPIO_MODE_USER_STD_OUTPUT;  // tdo
	
	/* Apply configuration */
	reg_mprj_xfer = 1;
	while (reg_mprj_xfer == 1);

}