Arcnet Circuit (Option Io-Pb14) - Casio TK-6500 Service Manual

6-13. ARCNET circuit (OPTION I/O PB14)
The ARCNET board I/O PB14 is option item for TK-6500.
It is possible to connect up to 32 units without scanning system through the ARCNET In-line
connection. TK-6500 has no scanning system.
1. ARCNET CHIP COM20019ILJP
Pin No. Pin Name
1 A0/nMUX
2 A1
3 A2/ALE
4 AD0
5 AD1
6 AD2
8 D3
9 D4
10 D5
11 D6
12 D7
27 nRD/nDS
Name In/Out Status of OFF
Address 0-2 In L
Data 0-7 In/Out L
In/Out L
In/Out L
In/Out L
In/Out L
In/Out L
In/Out L
In/Out L
nRead/ nData In L
Strobe
- 23 -
Status of ON Status of ON Description
No Token Token
L Pulse On a non-multiplexed bus,
these signals are directly
connected to the lower 3
bits of the address bus. on
the multiplexed address /
data bus, A0/nMUX is tied
low, A1 is left open, and
A2 is tied to the address
latch enable signal of the
host. A1is connected to an
internal pull-up resistor.
Pulse Pulse Input/Output. On a non-
Pulse Pulse multplexed bus, these
Pulse Pulse signals are used as the
Pulse Pulse lines fo the device. On a
Pulse Pulse multiplexed address/data
Pulse Pulse bus, AD-AD2 act as the
Pulse Pulse address lines (latched by
Pulse Pulse ALE) and as the low data
lines for the device. D3-D7
are always used for data
only. These signals are
connected to internal pull-
up resistors.
L Pulse Read/Data strobe signal
input. On a 68xx-like bus,
this active low signal is
issued by the
microcontroller as the data
strobe signal to strobe the
data onto the bus.
On a 80xx-like bus, this is
active low signal is issued
by the microcontroller to
indicate a read operation.