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[/] [s6soc/] [trunk/] [sw/] [dev/] [helloworld.c] - Blame information for rev 12

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1 12 dgisselq
////////////////////////////////////////////////////////////////////////////////
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//
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// Filename:    helloworld.c
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//
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// Project:     CMod S6 System on a Chip, ZipCPU demonstration project
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//
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// Purpose:     A very simple program.  This program tests the LEDs, buttons,
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//              and UART.  Specifically, if run, this program will cycle through
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//      the LEDs at one change per second.  If one button is pressed, it will
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//      cycle through turning one LED off once per second while turning the 
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//      rest on.  If the other button is pressed, two LED's will never turn on.
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//
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//      To test the UART, the message "Hello, world!" will be sent to the UART
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//      at the top of each second.
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//
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//      This program is simple.  Although it uses the interrupt controller,
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//      interrupts are disabled throughout the program.  The interrupt
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//      controller is only used to determine when events have taken place.
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//
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// Creator:     Dan Gisselquist, Ph.D.
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//              Gisselquist Technology, LLC
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//
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////////////////////////////////////////////////////////////////////////////////
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//
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// Copyright (C) 2015-2016, Gisselquist Technology, LLC
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//
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// This program is free software (firmware): you can redistribute it and/or
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// modify it under the terms of  the GNU General Public License as published
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// by the Free Software Foundation, either version 3 of the License, or (at
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// your option) any later version.
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//
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// This program is distributed in the hope that it will be useful, but WITHOUT
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// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
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// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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// for more details.
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//
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// You should have received a copy of the GNU General Public License along
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// with this program.  (It's in the $(ROOT)/doc directory, run make with no
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// target there if the PDF file isn't present.)  If not, see
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// <http://www.gnu.org/licenses/> for a copy.
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//
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// License:     GPL, v3, as defined and found on www.gnu.org,
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//              http://www.gnu.org/licenses/gpl.html
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//
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//
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////////////////////////////////////////////////////////////////////////////////
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//
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//
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#include "asmstartup.h"
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#include "board.h"
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const char msg[] = "Hello, world!\r\n";
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void entry(void) {
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        register IOSPACE        *sys = (IOSPACE *)IOADDR;
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        int     ledset = 0;
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        sys->io_spio = 0x0f0;
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        /// Turn off timer B
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        sys->io_timb = 0;
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        while(1) {
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                const char      *ptr;
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                sys->io_tima = TM_ONE_SECOND; // Ticks per second, 80M
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                sys->io_pic  = 0x07fffffff; // Acknowledge and turn off all ints
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                ptr = msg;
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                while(*ptr) {
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                        // Wait while our transmitter is busy
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                        while((sys->io_pic & INT_UARTTX)==0)
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                                ;
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                        sys->io_uart = *ptr++; // Transmit our character
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                        sys->io_pic  = INT_UARTTX; // Clear the int flag
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                }
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                // Now, wait for the top of the second
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                while((sys->io_pic & INT_TIMA)==0)
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                        ;
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                ledset <<= 1;
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                ledset &= 15;
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                if (ledset == 0)
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                        ledset = 1;
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                ledset |= 0xf0;
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                int     btn = sys->io_spio;
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                if (btn&0x10)
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                        sys->io_spio = ledset^0x0f;
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                else if (btn&0x20)
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                        sys->io_spio = ledset&0x0f5;
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                else
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                        sys->io_spio = ledset;
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        }
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}
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