Holtek HT-IDE, Руководство пользователя

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jmp get_key ;yes. get input info
mov a,0f7h ;(2) ;no. scan fourth row
mov matrix,a ;hold scan code
mov pac,a ;output pa.3 0 (latch)
mov a,pa ;read input state
cpl acc ;;complement input state
and a,0f0h ;;
sz acc ;if any input?
jmp get_key ;yes. get input info
jmp keyloop ;repeat from keyloop
get_key: ;get input key info
call delays ;debounce
mov a,pa ;test port A
or a,0fh ;
cpl acc ;
sz acc ;any key hold?
jmp go_on ;yes. go on (some key is pressed)
jmp keyloop ;no. return to scan key again
go_on:
call key_in ;(3) ;calculate table index
tabrdl disp ;(10) ;load display data
mov a,disp ;;output data to port B
mov pb,a ;(11) ;;
jmp keyloop ;repeat keyloop
key_in proc ;get key number
mov a,pa ;;hold port A state
mov temp,a ;(4) ;;
get_release: ;wait for the key to be released
mov a,pa ;test port A state
cpl acc ;
and a,0f0h ;
sz acc ;(6) ;if release?
jmp get_release ;no. keep up waiting
mov a,0fh ;yes. calculate key number
andm a,matrix ;(7) ;mask low nibble of scan code
mov a,0 ;keep table index at register A
get_row: ;calculate row number
rrc matrix ;check each bit to get row number
snz status.0 ;
jmp get_next ;if zero goto get_next
clr c ;
add a,4h ;(8) ;table index +4 (4 keys a row)
jmp get_row ;continue calculating
get_next: ;
mov tblp,a ;hold table index at register TBLP
mov a,0efh ;
mov mask,a ;mask=0111 1111
mov a,0fh ;
orm a,temp ;temp=XXXX 1111
HT-IDE User’s Guide
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