1 files changed, 65 insertions, 0 deletions
diff --git a/firmware/fx2/common/syncdelay.h b/firmware/fx2/common/syncdelay.h
new file mode 100644
index 000000000..0af7d099f
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+++ b/firmware/fx2/common/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_ */