link port loopback.txt

2005 Center for Biological & Computational Learning at MIT and MIT All rights reserved. Permissio

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link port loopback.zip      Example TS201 Link Port DMA Program

Analog Devices, Inc.
DSP Division
Three Technology Way
P.O. Box 9106
Norwood, MA 02062

07-22-2003 PPG 
MARCH 2004 PPG updated
	updated files cache_macros.h, LDF
	added project options for silicon revision issues
	built and tested under VisualDSP++ 3.5
	revised source to use interrupts
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Description:

This is a test of link to link DMAs on the TS201S EZ-Kit. LP3 is 
connected in a loopback of TX to RX (L3DAT(I/O)0_P/N) using single-bit 
data Loopback via external cable - Connect CAT5e cable to J4 (DSPA LP3 
TX) and J5 (DSPA LP3 RX) 

A single DXE will be built which can be loaded onto either DSPA or DSPB 
assuming required external link cable is connected for that DSP 
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Source Files contained in this directory:

Link Port Loopback.dpj		VisualDSP++ 3.5 project file
Link Port Loopback.asm		ADSP-TS101 source for multiprocessor DMA
ADSP-TS201_ASM.ldf			ADSP-TS201 Linker description file for 
							(single processor) 
cache_ macros.h				Header file with required macros for 
							embedded DRAM cache and BTB
tx_data.dat					data file
Link Port Loopback.txt		This file.
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Code flow:

Link Port Loopback.asm loads a buffer of data into link_data_tx, transmits it 
over the link port in loopback configuration with external cable using DMA into 
buffer link_data_rx.  A DMA interrupt for the receiver is used to indicate 
completion of the DMA transfer. After the DMA transfer completes, the 
transmitted data values are compared to the received data values and flag pins 
are toggled to indicate the results. Flag2 and flag3 connected to LEDs are 
toggled in unison to indicate failure when the received data values do not match 
the transmitted values. The same LEDs are toggled alternately to indicate 
success when the received data values match the transmitted values. 
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cache_macros.h
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After powerup/reset, the TS201 cache and BTB are not enabled

At the beginning of the program the cache must be enabled. The procedure is 
contained in the cache_enable macro that uses the refresh rate as input 
parameter
      -if CCLK=500MHz, refresh_rate=750
      -if CCLK=400MHz, refresh_rate=600
      -if CCLK=300MHz, refresh_rate=450
      -if CCLK=250MHz, refresh_rate=375

cache_macros.h performs the following:

-cache_enable(refresh_rate):
  -sets a new refresh rate
  -if the cache is enabled, it leaves it enabled.
  -if the cache is not enabled, it enables it in the correct way accounting for cache coherency
  -at the end enables the BTB if it was not already enabled
  -this macro should be used as the first line of code in every program

This header file also contains additional benchmarking macros which may be 
useful. Please see the header file source code and comments for additional 
information.
 

Project options: 
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Please refer to the VisualDSP++ release notes and the 
TS201S anomaly listing for full details of the following switch usage, 
operation and silicon revision requirements

Assembler/Compiler/Linker switches to be used in the assembler, linker,
and compiler property pages' Additional Options fields

'-si-revision 0.1'		Required for TS201S Rev 0.1 silicon. 
						Use in compiler AND Assembler AND linker property 
						page 'Additional Options' field.

If any example code projects are built/rebuilt for the above mentioned 
silicon revisions, these switches must be used. The same holds true for 
user created code sets.


For C language projects, the current working directory must also be specified. 
This is accomplished by placing a period (.) inside the "Additional Include 
Directories" field under Project Options | Compile | Category: Preprocessor. 
This project option will avoid the following warning: 
"[Warning pp0084] Include file not found in path; opening in connected directory."
which is incurred when using a statement similar to this: 
	asm("#include <cache_macros.h>"); 
where file 'cache_macro' resides in the current working project directory

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Notes:
1) This example code was specifically created for and tested on the 
TS201 EZ-Kit using an emulator for download, execution and observation of 
the results.
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