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PC-1600
9-4.
Gate array (LR38041) pin description
This gate array is an integration of ICs required for connec-
tion of LSls.
Pin
Symbol
ln/Out
Active
No.
level
Function
1 SLCB
In
It is an input of the sub CPU-issuedsignal PI which indicates commencement of the
svstem operation.
PI (SLCB) goeshigh when the system is off and does the following.
(1)
Data buses,D2~ 00, are fixed at a low level.
(2)
Except for A 13A, all outpur levels are fixed to low or high.
2
03
In
Hardware weak battery detect signal.
(1)
When a weak battery condition is detected, it forces 03 high; S1, S2, S3, KO, K1,
and K2 outputs areset high; KH outout is set low; and RD is set to high impedance
(inactive).
(2)
03 is at a low level when a weak battery is not established.
3 Z12 In
When on, the input is high.
4
Z13
In
Low
The sub CPU is normally in the sandby mode to savepower when a command is not
received. But, it would not go into the power savemode if the BREAK/ON key
is continuously depressed,asit goesout of the standby mode if KH is at a high level.
To prevent this, the state of the BREAK/ON key must
be
interrogated with Z13 when
required. During the power savemode, Z13 is set to high to keep the KH outpur at a
low level.
5 ON In
Low BREAK/ON key input.
The signal goeslow when the BREAK/ON key is depressed;otherwise,
it
is in a high
state.
6
KCl
In Signal input from the analog Input connector.
7
CL2 In
Sub CPU 1.229MHz clock Input,
8
RD
Out Low
Read signal created by five.signals (MEO,ME1,
00,
CKOS,and BRO) which are
externally wired OR with RD of the Z-80.
When the Z-80 is in operation, RD is at a high impedance.
9~16
R20~R33 In
Return data from the sub CPU. The data becomes the Z-80 data when the Z-80 reads
33H of 1/0.
17
PRIM
In
The PC-1600 has two serial Input/output interface: the RS-232C interface and the SIO
interface. But, either one must be assignedasonly one hardware is for the serial input/
outpur.
(1)
The SIO interface is selected with a low PRIM state.
(2)
The RS-232C interface is selected with a high PRIM state.
PRIME
=
"Low"
PRIME
=
"High"
Output SDA LOW
TXD
Output SDF
TXD
LOW
Input RXD RDF
RDA
18
TXD
In Low
Transmit data which is an output from the T8576F UART.
19
RXD
Out Low
Receive data which is an input to the T8576F UART.
20
RDA
In Low
Receive data which is an input from the RS-232C interface.
21
SDA
Out
High
Transmit data outpur is sent through the RS·232C interface connector. A low signal
state is sent when PRIM is at a low level.
22
RDF
In
High Receive data which is an input from the SIO interface.
23
SDF Out
High Transmit data which is an outpur to the SIO interface connector. A low signal state
is sent when PRIM is at a high level.
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