NEC PC-8201 Service Manual page 56

(If thc CI'U (80C85) is abnormal, see Item 6.2.3 "Abnormal CI'U".)
5.2.4 CPU Clock Operation Test
hleasure U 17, 80C85, (P37) of the CI' U clock.
Figure 5.5 shows the signal at U 17 (P37).
I
0.25ps
Figure 5.5 U17 (P37) Output Signal
*
If CPU CLOCK is abnormal. see Itern 6.2.4.
5 . 2 . 5 Calendar Cloclc Operation Test
hleasure whether the signal in Figure 5.6 is being transmitted to U20 (P10) of calendar
clock.
I
4ms
I
Figure 5.6 Calendar Clock Signal
(Reference
)
Figure
5.7
"Calendar Clock Peripheral Circuit"
*
If the calendar clock is abnormal, see
Item 6.2.5
"Abnormal Calendar Clock".
1
I
1
'
32~768K : : I 3 3-MR-2
RESET 9-CHI-9
9-CHI-4
I 1
KEY INT 1.U17-7
Figure
5.7 Calendar Clock Peripheral Circuit