Smemr# And Smemw# Generation; Memcs16# Generation - Epson SCE8720C Series Hardware Manual

CARD-PCI/GX Hardware Manual
A.2.6 SMEMR# and SMEMW# generation
As described in 4.10, SCE8720C's LIMITED ISA bus does not have SMEMR# or
SMEMW# signal. However, they can easily be generated in the circuit as shown below.
ROMCS#
MEMR#
MEMW#
Figure A.6 Circuit to generate SMEMR# and SMEMW#
A.2.7 MEMCS16# generation
To generate MEMCS16#, the condition ROMCS#=1 (BIOS ROM is not selected) is
necessary. If this condition is absent, error such as improper overwrite on BIOS ROM
might occur. Circuit example is shown below.
SA16
SA18
SA19
ROMCS#
SA17
72
ALS138 0
A 1
B 2
C 3
G1 4
G2A# 5
G2B# 6
7
Figure A.7 Circuit to generate ROMCS16#
*: MEMCS16# is active at D0000 to DFFFF.
EPSON
SMEMR#
SMEMW#
(*)
MEMCS16#
ALS05
Rev.A