Epson Research and Development
Page 23
Vancouver Design Center
Hardware Functional Specification
S1D13503
Issue Date: 01/01/29
X18A-A-001-08
IOW#
I
85
82
104
TTLS
In MC68000 MPU interface, this pin is connected to the R/W#
pin of MC68000. This input pin defines whether the data
transfer is a read (active high) or write (active low) cycle. In
other MPU/Bus interfaces, this is the active low input to write
data into an internal register.
IOR#
I
86
83
106
TTLS
In MC68000 MPU interface, this pin is connected to the AS#
pin of MC68000. This input pin indicates a valid address is
available on the address bus. In other MPU/Bus interfaces, this
is the active low input to read data from an internal register.
MEMCS#
I
87
84
107
TTLS
Active low input to indicate a memory cycle.
MEMW#
I
88
85
109
TTLS
Active low input to indicate a memory write cycle. This pin
should be tied to V
DD
in an MC68000 MPU interface.
MEMR#
I
89
86
110
TTLS
Active low input to indicate a memory read cycle. This pin
should be tied to V
DD
in an MC68000 MPU interface.
READY
O
90
87
112
TS3
For MC68000 MPU interface, this pin is connected to the
DTACK# pin of MC68000 and is driven low when the data
transfer is complete. In other MPU/Bus interfaces, this output
is driven low to force the system to insert wait states when
needed.
READY is placed in a high impedance (Hi-Z) state after the
transfer is completed.
RESET
I
32
29
37
TTLS
Active high input to force all signals to their inactive states.
Table 5-1: Bus Interface
Pin Name
Type
F00A
Pin #
F01A
Pin #
D00A
Pad #
Driver
Description
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