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contiki/backyard/core/dev/cs8900a.c

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/* UNFINISHED CODE: the code works, but has yet to be converted into
proper C code. It is mostly 6502 assembler for now. */
/*
* Copyright (c) 2001, Adam Dunkels.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This file is part of the C64 RealAudio server demo project.
*
* $Id: cs8900a.c,v 1.1 2007/05/26 22:00:33 oliverschmidt Exp $
*
*/
/* cs8900a.c: device driver for the CS8900a chip in 8-bit mode. Mostly
written in 6502 assembler for speed. */
#include "cs8900a.h"
#include "uip.h"
#include "uip_arp.h"
#define UIP_ETHADDR0 0x00
#define UIP_ETHADDR1 0x00
#define UIP_ETHADDR2 0x00
#define UIP_ETHADDR3 0x64
#define UIP_ETHADDR4 0x64
#define UIP_ETHADDR5 0x64
extern u8_t *cs8900a_rxtxreg,
*cs8900a_txcmd,
*cs8900a_txlen,
*cs8900a_packetpp,
*cs8900a_ppdata;
static u16_t len;
static u8_t r;
#define WRITE(P, D) do { PACKETPP = (P); \
PPDATA = (D); } while(0)
/*-----------------------------------------------------------------------------------*/
void
cs8900a_init(void)
{
/* Turn on transmission and reception of frames. */
WRITE(0x0112, 0x00c0);
/* Accept valid unicast+broadcast frames. */
WRITE(0x0104, 0x0d05);
/* Set MAC address. */
WRITE(0x0158, (ETHADDR1 << 8) | (ETHADDR0));
WRITE(0x015a, (ETHADDR3 << 8) | (ETHADDR2));
WRITE(0x015c, (ETHADDR5 << 8) | (ETHADDR4));
}
/*-----------------------------------------------------------------------------------*/
void
cs8900a_send(void)
{
if(uip_len > UIP_BUFSIZE) {
return;
}
/* Transmit command. */
/* *cs8900a_txcmd = 0x00c0 */
asm("lda #$c0");
asm("sta %v", cs8900a_txcmd);
asm("lda #$00");
asm("sta %v+1", cs8900a_txcmd);
/* *cs8900a_txlen = uip_len */
asm("lda _uip_len");
asm("sta %v", cs8900a_txlen);
#if UIP_BUFSIZE > 255
asm("lda _uip_len+1");
#else
asm("lda #0");
#endif
asm("sta %v+1", cs8900a_txlen);
asm("ldx #8");
asm("tryagain:");
/* Check for avaliable buffer space. */
asm("lda #$38");
asm("sta %v", cs8900a_packetpp);
asm("lda #$01");
asm("sta %v+1", cs8900a_packetpp);
asm("lda %v+1", cs8900a_ppdata);
asm("and #1");
asm("bne send");
/* No space avaliable, skip a received frame and try again. */
asm("lda #$02");
asm("sta %v", cs8900a_packetpp);
asm("lda #$01");
asm("sta %v+1", cs8900a_packetpp);
asm("lda %v", cs8900a_ppdata);
asm("ora #$40");
asm("sta %v", cs8900a_ppdata);
asm("dex");
asm("bne tryagain");
asm("bailout:");
return;
/* Send the frame. */
asm("send:");
/* First, send 40+14=54 bytes of header. */
asm("ldx #54");
asm("ldy #0");
asm("sendloop1:");
asm("lda _uip_buf,y");
asm("sta %v", cs8900a_rxtxreg);
asm("lda _uip_buf+1,y");
asm("sta %v+1", cs8900a_rxtxreg);
asm("iny");
asm("iny");
asm("dex");
asm("dex");
asm("bne sendloop1");
if(uip_len <= 54) {
return;
}
/* Next, send rest of the packet. */
uip_len -= 54;
asm("lda ptr1");
asm("pha");
asm("lda ptr1+1");
asm("pha");
asm("lda _uip_appdata");
asm("sta ptr1");
asm("lda _uip_appdata+1");
asm("sta ptr1+1");
asm("sendloop2:");
asm("lda _uip_len");
asm("tax");
asm("and #1");
asm("beq noinc");
asm("inx");
asm("noinc:");
#if UIP_BUFSIZE > 255
asm("lda _uip_len+1");
#else
asm("lda #0");
#endif
asm("beq nozero");
asm("ldx #0");
asm("nozero:");
asm("ldy #0");
asm("sendloop:");
asm("lda (ptr1),y");
asm("sta %v", cs8900a_rxtxreg);
asm("iny");
asm("lda (ptr1),y");
asm("sta %v+1", cs8900a_rxtxreg);
asm("iny");
asm("dex");
asm("dex");
asm("bne sendloop");
asm("inc ptr1+1");
#if UIP_BUFSIZE > 255
asm("dec _uip_len+1");
asm("bpl sendloop2");
#endif
asm("pla");
asm("sta ptr1+1");
asm("pla");
asm("sta ptr1");
}
/*-----------------------------------------------------------------------------------*/
static void
skip_frame(void)
{
WRITE(0x0102, PPDATA | 0x0040);
}
/*-----------------------------------------------------------------------------------*/
u8_t
cs8900a_poll(void)
{
/* Check receiver event register to see if there are any valid
unicast frames avaliable. */
/* PACKETPP = 0x0124;
if(PPDATA & 0x000d == 0x0000) {
return 0;
}
*/
asm("lda #$24");
asm("sta %v", cs8900a_packetpp);
asm("lda #$01");
asm("sta %v+1", cs8900a_packetpp);
asm("lda %v+1", cs8900a_ppdata);
asm("and #$0d");
asm("cmp #$00");
asm("bne noreturn");
/* No frame ready. */
return 0;
asm("noreturn:");
/* Process the incoming frame. */
/* Read receiver event and discard it. */
/* dummy = RXTXREG; */
asm("lda %v+1", cs8900a_rxtxreg);
asm("sta _len+1");
asm("lda %v", cs8900a_rxtxreg);
asm("sta _len");
/* Read frame length. */
/* len = uip_len = RXTXREG; */
asm("lda %v+1", cs8900a_rxtxreg);
asm("sta _len+1");
asm("sta _uip_len+1");
asm("lda %v", cs8900a_rxtxreg);
asm("sta _len");
asm("sta _uip_len");
if(len > UIP_BUFSIZE) {
skip_frame();
return 0;
}
/* Read bytes into uip_buf. */
asm("lda ptr1");
asm("pha");
asm("lda ptr1+1");
asm("pha");
asm("lda #<_uip_buf");
asm("sta ptr1");
asm("lda #>_uip_buf");
asm("sta ptr1+1");
asm("lda _len+1");
asm("beq read256");
/* Read first 256*n bytes. */
asm("ldy #0");
asm("read256loop:");
asm("lda %v", cs8900a_rxtxreg);
asm("sta (ptr1),y");
asm("iny");
asm("lda %v+1", cs8900a_rxtxreg);
asm("sta (ptr1),y");
asm("iny");
asm("bne read256loop");
asm("inc ptr1+1");
asm("dec _len+1");
asm("bne read256loop");
/* Read last 255 or less bytes. */
asm("read256:");
asm("lda _len");
asm("lsr");
asm("bcc noinc");
asm("inc _len");
asm("noinc:");
asm("ldy #$0");
asm("readloop:");
asm("lda %v", cs8900a_rxtxreg);
asm("sta (ptr1),y");
asm("iny");
asm("lda %v+1", cs8900a_rxtxreg);
asm("sta (ptr1),y");
asm("iny");
asm("cpy _len");
asm("bne readloop");
asm("pla");
asm("sta ptr1+1");
asm("pla");
asm("sta ptr1");
return len;
}
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