Sharp PC-1600

-
PC-l600
Pin
Symbol
ln/Out
Active State
Function
No.
level at ACL
Vcc
~~~
~
* [QH] Z13;;__j
KH
,~
Z13
BREAK
I
J
lQS]
KH
20
Z12 Out
Low
In For the PC-1600, a high signal state is normally issued (at ON).
21
Z11 In In NC.
22
Z10
Out
High In This signal is usedto interface with the main CPU. it goes high when the
sub CPU waits for a command (ready), and goes low when busv.
23 Z9 Out
High In
This signal is also used to interface with the main CPU. A high pulse is
issuedwhen the sub CPU terminates a command execution.
24
Z8 Out In
Used to setup the analog input mode.
(1)
Voltage is A/D converted when low (initial value). The input impedance
is 100K ohms.
(2)
Current is A/D converted when high.
The PC·1600 supports (1) in BASIC, but it needs to program in machine
languagefor (2).
25 Z7 Out
High In
The sub CPU setsthis signal high when the command specified interrupt has
been acknowledged. This signal is connected to INT6 input of the SC7852.
,
There are four causes which force this signal level to high.
(I)
The weke-up time matched the real-time timer.
(11) The time of alarm-1 or -2 matched the real-time timer.
(111)Receipt of an Input from the external keyboard.
(IV) At 0.5 second cycle of the real-time timer.
This signal goeslow when the interrupf causestatus is read or when all Inputs
from the external keyboard have been read.
26
GND
±OV
27
Z6 Out Low
In A 1/64 second pulse of 50% dutv is sent.
Connected to INT4 and PB5 inputs of the SC7852.
28
Z5
Out
High In As the reference voltage is required when the sub CPU A/D converts the signal
input to KCO~KC2, Z5 is set high only during the A/D conversion to obtain
the correct VRH. This is used for VRH accuracy asweil as power saving.
29
Z4
Out
High In Used for handshaking of the external keyboard Input through the analog
input connector.
Shorted with the analog input KC1.
Normally an open outpur.
30
Z3 In In
31
Z2 In In
32
Zl
In In
Not used.
33
ZO In In
34 SOUT
Out
35
SCLOCK
ln/Out
In
36
F
Out
,
tJsedfor generation of click and alarm sounds.
37
VRH In
A/D conversion high side reference voltage (2.475V in supply).
--~
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-~~
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