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Epson Research and Development
Vancouver Design Center
S1D13503
ISA Bus Interface Considerations
X18A-G-003-05
Issue Date: 01/01/30
2 16-BIT ISA BUS INTERFACE
For the purpose of the example shown below, the following conditions apply:
1.
Indexed I/O with addresses 0310h and 0311h (see Configuration Options)
2.
128Kbytes of display memory occupying $C and $D segments (see Configuration Options)
Note
This memory configuration will conflict with a VGA card installed on the same bus, therefore either a
serial terminal or monochrome display adapter is recommended as the primary console.
This section provides the necessary logic equations and settings to complete the interface between the S1D13503 and the
16-bit ISA Bus.
Note
A PAL was used instead of discrete logic to reduce external component count.
Figure 1: 16-Bit ISA Bus Implementation
A
1
2
3
IOCS#
MEMCS#
AB0-19
BHE#
DB0-15
MEMW
MEMR
IOW#
IOR#
READY
B
74LS09
4
5
6
AEN
REFRESH
SA0-19
SBHE#
SD0-15
SMEMW#
SMEMR#
IOW#
IOR#
IOCHRDY
10k
Ω
V
CC
VD0,VD7,
VD14-15
VD11-12,
IOCS16#
LA17-23
MEMCS16#
74LS688
0000110 (q0-6)
LA23-17 (p0-6)
P
Q
G
IOCS16EN
PAL
16-Bit ISA Bus
S1D13503
SA1-15
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