8XC196MC, MD, MH USER’S MANUAL

;followed by a short (1 ms) pause, thus generating a MFM waveform.

;This program is assembled to run on the MD demo board.

;

;**************************************

;CONSTANT AND VARIABLE DECLARATIONS ;**************************************

;Program equates

;This section defines the constants used by this program.

;They can be changed at assembly time as required. ;**************************************

zero_time

equ

1000

;1 ms

zero_pause_time

equ

zero_time

 

one_time

equ

2000

;2 ms

one_pause_time

equ

one_time

 

carrier_freq

equ

25

;40 KHz

buf_size

equ

8

;size of data buffer (bytes)

fill_char

equ

10100011b

;initial data for buffer

;

 

 

 

;**************************************

;SFR equates in a 32-byte window

;This section defines SFR locations as seen through a window

;to allow using compact read-modify-write instructions. ;**************************************

p2_mode_w

equ

0f0H

;WSR = 7EH

1FD0H

p2_dir_w

equ

0F2H

;WSR = 7EH

1FD2H

p2_reg_w

equ

0F4H

;WSR = 7EH

1FD4H

p2_pin_w

equ

0F6H

;WSR = 7EH

1FD6H

;

 

 

 

 

p7_mode_w

equ

0f1H

;WSR = 7EH

1FD1H

p7_dir_w

equ

0F3H

;WSR = 7EH

1FD3H

p7_reg_w

equ

0F5H

;WSR = 7EH

1FD5H

p7_pin_w

equ

0F7H

;WSR = 7EH

1FD7H

;

 

 

 

 

timer1_w

equ

0FAH

;WSR = 7BH

1F7AH

comp3_con_w

equ

0E4H

;WSR = 7BH

1F64H

comp3_time_w

equ

0E6H

;WSR = 7BH

1F66H

;

 

 

 

 

;**************************************

;Other SFR equates

;This section defines the locations of the frequency generator SFRs. ;**************************************

freq_gen equ 1FB8H

freq_cnt

equ

1FBAH

;

 

 

;**************************************

;Variable storage area

;This section defines the variables used by this program. ;**************************************

rseg at 30h

rism:

dsb 13

;reserved for RISM

;

 

 

rseg at 40h

 

 

8-6

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Intel 8XC196MH, 8XC196MD, 8XC196MC manual 0FAH