Sharp MZ-80B Owner's Manual page 91

82
Figures 3.0-SA and 3.0-SB illustrate how a programmable counter can be used to extend interrupt acknowledge
time . (Configured as shown to add one wait state)
74S04
~
IORQ
~0-~-TE- 0 R_I_P_H_E_R-AL)
~WAIT
.---t---oL:}
0- (- T _O_C_P_U_ ) _
IORQ-·-----j
<I>
----o
- ~
M 1 - - Q L : J
LAST T
STATE · o~
I
LAST M CYCLE OF
INSTRUCTION
+ 5V
EXTENDING INTERRUPT ACKNOWLEDGE TIME WITH WAIT STATE
FIGURE 3.0-5A
AUTOMATIC WAIT-.,-\------,\
USER WAIT
Tw
*
Tw
*
Tw
--------------~~~-------------------------r------~-----JX~-----
M1
DATA BUS
- -
NORMAL ACKNOWLEDGE_
TIME -
\~----~------~---~
I----ACKNOWLEDGE TIME WITH ONE
ADDITIONAL WAIT STATE
----+
REQUEST/ACKNOWLEDGE CYCLE WITH ONE ADDITIONAL WAIT STATE
FIGURE 3.0-58