syncdelay.h

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/* -*- c++ -*- */
/*
 * Copyright 2003 Free Software Foundation, Inc.
 * 
 * This file is part of GNU Radio
 * 
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 * 
 * GNU Radio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */
#ifndef _SYNCDELAY_H_
#define _SYNCDELAY_H_

/*
 * Magic delay required between access to certain xdata registers (TRM page 15-106).
 * For our configuration, 48 MHz FX2 / 48 MHz IFCLK, we need three cycles.  Each
 * NOP is a single cycle....
 *
 * From TRM page 15-105:
 *
 * Under certain conditions, some read and write access to the FX2 registers must
 * be separated by a "synchronization delay".  The delay is necessary only under the
 * following conditions:
 *
 *   - between a write to any register in the 0xE600 - 0xE6FF range and a write to one
 *     of the registers listed below.
 *
 *   - between a write to one of the registers listed below and a read from any register
 *     in the 0xE600 - 0xE6FF range.
 *
 *   Registers which require a synchronization delay:
 *
 *      FIFORESET                       FIFOPINPOLAR
 *      INPKTEND                        EPxBCH:L
 *      EPxFIFOPFH:L                    EPxAUTOINLENH:L
 *      EPxFIFOCFG                      EPxGPIFFLGSEL
 *      PINFLAGSAB                      PINFLAGSCD
 *      EPxFIFOIE                       EPxFIFOIRQ
 *      GPIFIE                          GPIFIRQ
 *      UDMACRCH:L                      GPIFADRH:L
 *      GPIFTRIG                        EPxGPIFTRIG
 *      OUTPKTEND                       REVCTL
 *      GPIFTCB3                        GPIFTCB2
 *      GPIFTCB1                        GPIFTCB0
 */

/*
 * FIXME ensure that the peep hole optimizer isn't screwing us
 */
#define SYNCDELAY       _asm nop; nop; nop; _endasm
#define NOP             _asm nop; _endasm


#endif /* _SYNCDELAY_H_ */