readme.txt

提供了一些ADSP-217x或ADSP-218x DSP芯片的编程事例

/********************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*				   ADSP-21xx Specific Code version 1.0	
*
* By  :	Jaap de Jong ([e-mail])
*	Nedap Retail Support
*	Parallelweg 2d
*	Postbox 102
*	7140 AC Groenlo
*	Netherlands
* Based on 'ADSP-21065L SHARC Specific Code version 1.0' by Bertrand Hurst, Francois Veuve, Cedric Bornand
********************************************************************************************************/

This file contains:

1) "ADSP-21xx Specific Code" package content description
2) Short explanations about the provided files
3) Used resources, software restrictions
4) How to compile and run
5) Common timing and memory usage
6) License agreement
7) Warranty disclaimer


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1) "ADSP-21xx specific Code" package content description

This package contains all the files needed to make uC/OS-II running
on an ADSP-217x or ADSP-218x DSP from Analog Devices.

There should be 8 files in this package:

readme.txt      This file
2186.des	Architecture file
os_cfg.h        Config file
os_cpu.h        Type definition file
os_cpu_c.c      C functions for the 21xx port
os_cpu_a.dsp    Assembly functions for the 21xx port
example_c.c     A small example program, that toggles two lines
example_a.dsp   Extra functions the example program
includes.h	Includes file
make.bat	Build this demo


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2) Short explanations about the provided files

2.1) File 2186.des

Description of the hardware. No further comments. Change this for
other 21xx processors.


2.2) File os_cfg.h

This code is only suitable for 217x and	218x processors due to the 
usage of ENA/DIS INTS.


2.3) File os_cpu.h

There is not much to tell about that file. It contains the definition
of all the types used in the other files, to ensure that the C source
code of uC/OS-II may be compiled. Just note that all registers and the
memory are 16-bits wide in the 21xx DSPs, so 8-bits types are mapped
in 16-bits.


2.4) File os_cpu_c.c

This file just contains the OSTaskStkInit function. Some registers must
have a special value because the compiler counts on it. 
Please have a look to the section 3 below, it gives some important
information about stack usage.

The empty hook functions described in that file are called accordingly
to uC/OS-II standard, and may be used for any purpose that you'll find
suitable.


2.5) File os_cpu_a.dsp

One heavy macro to put (almost) all registers on the stack, and one
heavy routine to restore them.
Finally, there are four functions, all reasonably straightforward.
A special label, named ___lib_tmri_ctrl, pointing at OSTickISR_, is 
used to get the interruptvectors in its place. This is done by the 
compiler.
This code is suitable for any 21xx processor.


2.6) File example_c.c

This file is provided to help compiling a first program. It toggles
the PF2 and PF3 outputs at a different rate.

Just note in the TaskStart function that the timer_*() functions are
called to initialize the DSP timer.


2.7) File example_a.dsp

Some simple assembly routines needed to toggle the outputs and a routine
to enable timerinterrupts.


2.8) File includes.h

No comment. 


2.9) File make.bat

Just to make it a bit easy...
Note the -mno-doloops option for g21.exe. This will disable the generation
of DO-UNTILS in the code. Beware: this is only for the compiler, library
functions will still contain DO-UNTILS...


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3) Used resources, software restrictions

The only resource used by the OS is the timer. 

There are some restrictions about the application software. As saving
all registers takes a LOT of time (about 60 registers!), some
optimizations have been made: the stacks does not contain every
registers. Here is the list of the unsaved registers:

Registers	Meaning...
---------	------------------
I4		Stack ptr, used by C compiler
L4		Always 0
IMASK		Global use
MSTAT		Global use
STATUS STACK	Don't use POP/PUSH STS
LOOP regs	Since the loopstack can't be read by the processor, there
		are no DO-UNTIL's allowed. Beware of library functions!!
Secondary regs	Don't use

If you want to use any of these registers, disable interrupts while using
them.

All these restrictions are also made by the C compiler, so, as long as
you don't code anything in assembly, you won't have to worry.

WARNING!!! Pay attention to the provided C runtime library!!! It contains
assembly functions that may use some of the above registers!!! So be
very carefull when using runtime library functions...
Here is a list of library functions that use DO-UNTILS:
	BIQUAD.DSP	
	CALLOC.DSP
	DEMEAN.DSP
	DI_DIV.DSP
	DSI_DIV.DSP
	FFT.DSP
	FIR.DSP
	FIRB.DSP
	FREE.DSP
	GSMSH.DSP
	IIR.DSP
	LIB_FPDI.DSP
	MALLOC.DSP
	MATADD.DSP
	MATMUL.DSP
	MATSMLT.DSP
	MATSUB.DSP
	MEMCMP.DSP
	MEMCPY.DSP
	MEMCPYDP.DSP
	MEMCPYPD.DSP
	MEMCPYPP.DSP
	MEMSET.DSP
	MFIR.DSP
	NEW_DIV.DSP
	PLATT.DSP
	SIN.DSP
	STRCAT.DSP
	STRCMP.DSP
	STRCPY.DSP
	STRLEN.DSP
	STRNCAT.DSP
	STRNCMP.DSP
	STRNCPY.DSP
	ZLATT.DSP
Most of them can easily be rewritten... Left as an exercise to the reader...


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4) How to compile and run

All test have been made with ADDS-21XX-SW-PC-v6.1
Just doubleclick make.bat and download the image to your target or use
the debugger.


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5)  Common timings and memory usage

With all uC/OS-II functions enabled, the generated code takes about 5500
instructions. 
With a 32 MHz DSP, a task switch takes about 6 to 10 microsecond (think about the
huge amount of registers to save!).


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6) License agreement

THE TERMS AND CONDITIONS THAT APPLY TO 礐/OS-II ALSO APPLY TO THE 
ADSP-21xx Specific Code.


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7) Warranty disclaimer

YOU USE THIS SOFTWARE AT YOUR OWN RISK. THE AUTHORS WON'T
BE LIABLE FOR ANY SPECIAL OR CONSEQUENTIAL DAMAGES (INCLUDING BUT NOT 
LIMITED TO LOSS OF PROFITS) WHILE USING OR MISUSING THIS SOFTWARE.


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