**************************************************************************
**        DUAL-TONE MODULATED FREQUENCY GENERATOR FOR THE 'C542         **
**                        (DTMF GENERATOR ONLY)                         **
**************************************************************************
**                          Texas Instruments, Inc.	 	        **
**                          Date: Mar 03, 1997                          **
**************************************************************************

About the DSP Source code:
--------------------------
The code below was written using the 'C54x DSKplus board Debugger.
Code is loaded into the DSK using the 'C54x debugger interface or the DSK
LoadApp. Upon execution, the DSK output will generate a 2-tone (DTMF)
frequency corresponding to the telephone keypad digits found at the label
'NUMBR'. Digits 1-9 are generated using 1-9. Digits *,0,# are generated
using '0ah', '0bh' and '0ch' repectively. See the keypad below:

                                Column
                           1       2       3

                       +-----------------------+
                 1     |   1   |   2   |   3   |
                       |       |       |       |
                       +-------+-------+-------+
                 2     |   4   |   5   |   6   |
              R        |       |       |       |
              O        +-------+-------+-------+
              W  3     |   7   |   8   |   9   |
                       |       |       |       |
                       +-------+-------+-------+
                 4     |   *  _|   0  _|   #  _|
                       |     |a|     |b|     |c|
                       +-----------------------+

Each number to be dialed must be followed by a comma. The phone number must
end with a '-1'. One second delays can be inserted between digits for a
pausing effect. Here is an example phone number:

 NUMBR  .word  1,7,1,3,2,7,4,2,3,2,3,0,0,1,0bh,2,3,-1
               \___________________/ \ / \_______/ \/
                         |            |      |      Stop word
                   Phone number      Two     |
                 (1-713-274-2323)   second   |
                                    pause    |
                                           password,
                                             etc.
                                           (1023)


Using the Code Explorer Debugger:
---------------------------------
The DSP code uses the same interrupt as the Debugger. This will cause the Debugger
receive erroneous interrupts. In order to debug the code comment out the following
line of source code:
			 hpic =  #0ah             ; done.

Once this line has been commented-out and the source code re-assembled, you can 
single-step and debug the code.


Using the WDialer.exe Windows App:
----------------------------------
The WDialer application loads the DSKplus with the default kernel and proceeds to 
load the DTMF54X.OBJ application file. The WDialer application also loads a phone
list file called 'phone.ato'. The application and phone list files are reqired to be
in the same directory as the Wdialer executable. 


Manual Dialing:
---------------
Click on a number from the keypad to dial. OR Manually type the phone number in the
'Number' field and click 'Dial'.

Phone List Dialing:
-------------------
Click on the name in the 'Phone List' box you would like to dial. The telephone 
number will appear in the 'Number' field. Click on 'Dial' to dial the number.

Phone.ato Format:
-----------------
The phone list is an ASCII file which can be edited with any simple editor. Always
delimit the name and phone number with a colon (:). The first line on the phone list 
must say "Phone List" to be considered valid.
