Mikroelektronika MIKROE-742 데이터 시트

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

function Ps2_Key_Read(var value: byte; var special: byte; var
pressed: byte): byte;

- 

1

if reading of a key from the keyboard was successful 

- 

0

if no key was pressed 

The function retrieves information on key pressed.

Parameters : 

- 

value

: holds the value of the key pressed. For characters, numerals, punctua

tion marks, and space value will store the appropriate ASCII code. Routine 
“recognizes” the function of Shift and Caps Lock, and behaves appropriately. 
For special function keys see Special Function Keys Table. 
special: is a flag for special function keys (F1, Enter, Esc, etc). If key pressed 
is one of these, special will be set to 1, otherwise 0. 

- 

pressed

: is set to 1 if the key is pressed, and 0 if it is released. 

PS/2 keyboard needs to be initialized. See Ps2_Config routine.

var value, special, pressed: byte;
...
// Press Enter to continue:
repeat

if (Ps2_Key_Read(value, special, pressed)) then

if ((value = 13) and (special = 1)) then break;  

until (0=1);