OpenCores
URL https://opencores.org/ocsvn/neorv32/neorv32/trunk

Subversion Repositories neorv32

[/] [neorv32/] [trunk/] [sw/] [example/] [blink_led/] [main.c] - Blame information for rev 62

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 zero_gravi
// #################################################################################################
2
// # << NEORV32 - Blinking LED Demo Program >>                                                     #
3
// # ********************************************************************************************* #
4
// # BSD 3-Clause License                                                                          #
5
// #                                                                                               #
6 44 zero_gravi
// # Copyright (c) 2021, Stephan Nolting. All rights reserved.                                     #
7 2 zero_gravi
// #                                                                                               #
8
// # Redistribution and use in source and binary forms, with or without modification, are          #
9
// # permitted provided that the following conditions are met:                                     #
10
// #                                                                                               #
11
// # 1. Redistributions of source code must retain the above copyright notice, this list of        #
12
// #    conditions and the following disclaimer.                                                   #
13
// #                                                                                               #
14
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #
15
// #    conditions and the following disclaimer in the documentation and/or other materials        #
16
// #    provided with the distribution.                                                            #
17
// #                                                                                               #
18
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to  #
19
// #    endorse or promote products derived from this software without specific prior written      #
20
// #    permission.                                                                                #
21
// #                                                                                               #
22
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS   #
23
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF               #
24
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE    #
25
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,     #
26
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
27
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED    #
28
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING     #
29
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  #
30
// # OF THE POSSIBILITY OF SUCH DAMAGE.                                                            #
31
// # ********************************************************************************************* #
32
// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
33
// #################################################################################################
34
 
35
 
36
/**********************************************************************//**
37
 * @file blink_led/main.c
38
 * @author Stephan Nolting
39
 * @brief Simple blinking LED demo program using the lowest 8 bits of the GPIO.output port.
40
 **************************************************************************/
41
 
42
#include <neorv32.h>
43
 
44
 
45
/**********************************************************************//**
46
 * @name User configuration
47
 **************************************************************************/
48
/**@{*/
49
/** UART BAUD rate */
50
#define BAUD_RATE 19200
51 37 zero_gravi
/** Use the custom ASM version for blinking the LEDs defined (= uncommented) */
52
//#define USE_ASM_VERSION
53 2 zero_gravi
/**@}*/
54
 
55
 
56
/**********************************************************************//**
57 37 zero_gravi
 * ASM function to blink LEDs
58 23 zero_gravi
 **************************************************************************/
59
extern void blink_led_asm(uint32_t gpio_out_addr);
60
 
61 37 zero_gravi
/**********************************************************************//**
62
 * C function to blink LEDs
63
 **************************************************************************/
64
void blink_led_c(void);
65 23 zero_gravi
 
66 37 zero_gravi
 
67 23 zero_gravi
/**********************************************************************//**
68 22 zero_gravi
 * Main function; shows an incrementing 8-bit counter on GPIO.output(7:0).
69 2 zero_gravi
 *
70 22 zero_gravi
 * @note This program requires the GPIO controller to be synthesized (the UART is optional).
71 2 zero_gravi
 *
72 60 zero_gravi
 * @return 0 if execution was successful
73 2 zero_gravi
 **************************************************************************/
74
int main() {
75
 
76 51 zero_gravi
  // init UART (primary UART = UART0; if no id number is specified the primary UART is used) at default baud rate, no parity bits, ho hw flow control
77
  neorv32_uart_setup(BAUD_RATE, PARITY_NONE, FLOW_CONTROL_NONE);
78 22 zero_gravi
 
79 2 zero_gravi
  // check if GPIO unit is implemented at all
80
  if (neorv32_gpio_available() == 0) {
81 22 zero_gravi
    neorv32_uart_print("Error! No GPIO unit synthesized!\n");
82 61 zero_gravi
    return 1; // nope, no GPIO unit synthesized
83 2 zero_gravi
  }
84
 
85
  // capture all exceptions and give debug info via UART
86
  // this is not required, but keeps us safe
87 14 zero_gravi
  neorv32_rte_setup();
88 2 zero_gravi
 
89
  // say hello
90
  neorv32_uart_print("Blinking LED demo program\n");
91
 
92 23 zero_gravi
 
93 37 zero_gravi
// use ASM version of LED blinking (file: blink_led_in_asm.S)
94
#ifdef USE_ASM_VERSION
95
 
96
  blink_led_asm((uint32_t)(&GPIO_OUTPUT));
97
 
98 23 zero_gravi
// use C version of LED blinking
99 37 zero_gravi
#else
100 23 zero_gravi
 
101 37 zero_gravi
  blink_led_c();
102
 
103
#endif
104
  return 0;
105
}
106
 
107
 
108
/**********************************************************************//**
109
 * C-version of blinky LED counter
110
 **************************************************************************/
111
void blink_led_c(void) {
112
 
113 62 zero_gravi
  neorv32_gpio_port_set(0); // clear gpio output
114 2 zero_gravi
 
115
  int cnt = 0;
116
 
117
  while (1) {
118 22 zero_gravi
    neorv32_gpio_port_set(cnt++ & 0xFF); // increment counter and mask for lowest 8 bit
119
    neorv32_cpu_delay_ms(200); // wait 200ms using busy wait
120 2 zero_gravi
  }
121
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.