Sharp MZ-5500 Tehnical Manual

iv) Interrupt eyele eomputing method and time faetor setup
The software timer interrupt eyele must be obtained with the " following
formula.
t = K x T / 19200
~lere, t: Interrupt eyele [s]
T: Time faetor ... Value set in the CTC
o must be handled as 256.
K: Constant dependent on the ehannel
Ch 3: 16
Ch 4: 1
Ch 5: 16
Ch 6: 16
eh 7: 64
Sinee the ehannel 3 is already used by the system, ehannels, 4 to 7, must be
used.
Ex: To generate interrupt at every lOms on the ehannel 6.
Time eonstant
CT)
10 x 10-
3
x 19200 / 16 = 12
MOV
DX, 216H
MOV AL, OC5H
OUT
DX,
AL
MOV AL,
12
OUT
DX, AL
To disable interrupt to the ehannel 6.
MOV DX, 216H
MOV AL, 4lH
OUT DX, AL
NOTE:
Range of the time [aetor set in the CTC is as foliows:
o to 255 ("0" slgnifies "256")
I.
3G

Sharp MZ-5500 Specifications

General

Brand	Sharp
Model	MZ-5500
Category	Desktop
Language	English