Hi, could someone please guide me about how we can change the various wishbone signals including the i_wb_data, i_wb_addr, i_wb_en, etc.? Like, if I need to read certain data at a certain time from the wishbone, how do I go about doing that. @Matt Venn uses the following wishbone example: Whilst testing it, the firmware is as follows:

#include "verilog/dv/caravel/defs.h"
#include "verilog/dv/caravel/stub.c"

/*
	IO Test:
		- Configures MPRJ lower 8-IO pins as outputs
		- Observes counter value through the MPRJ lower 8 IO pins (in the testbench)
*/

#define reg_wb_leds      (*(volatile uint32_t*)0x30000000)
#define reg_wb_buttons   (*(volatile uint32_t*)0x30000004)


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

	// 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.

	// Configure lower 8-IOs as user output
	// Observe counter value in the testbench
	reg_mprj_io_7 =  GPIO_MODE_USER_STD_INPUT_NOPULL;
	reg_mprj_io_8 =  GPIO_MODE_USER_STD_INPUT_NOPULL;
	reg_mprj_io_9 =  GPIO_MODE_USER_STD_INPUT_NOPULL;

	reg_mprj_io_10 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_11 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_12 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_13 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_14 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_15 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_16 =  GPIO_MODE_USER_STD_OUTPUT;
	reg_mprj_io_17 =  GPIO_MODE_USER_STD_OUTPUT;

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

    // wait for all 3 buttons to get pressed
    while (reg_wb_buttons != 7);

    // then set all the leds, signalling the end of the test
    reg_wb_leds = 0xFF;

}

Where are the wishbone signals being set? I'm new to this harness, any help would be appreciated~!

a memory address is made reg_wb_leds, and then writing to that writes to memory, which then gets sent over the wishbone bus

So it's sent whenever it's written, in this case, it's written via the firmware when we set reg_wb_leds=0xFF?