Ram and flash decode – Zilog Z8F0411 User Manual
Page 34
MDS General-Purpose Board Development Kit
User Manual
UM016905-1207
MDS-GP Board Features
29
Due to possible electromagnetic interference (EMI) from the
circuitry surrounding the dinsmore 1490 digital compass,
Zilog
®
recommends mounting this device off-board using a
short ribbon cable.
RAM and Flash Decode
The MDS-GP board includes 512 KB fast SRAM, device U22. This
memory can only be used by MDS-PM board that supports an external
address/data bus.
The MDS-GP board also includes two footprints on the back of the board
for adding user- installed flash memory devices. Zilog
®
cannot control the
quality of added flash devices or their installation, so use these footprints
at your own risk.
Address decoding for the included SRAM, external I/O bus (see
on page 10), and user- installed flash is factory programmed
by PAL U26, as shown in
Table 4. PAL U26 Decode
Chip
Select
Device
Decode
Address
A23 A22 A21 A20
CS2
512 KB SRAM, U22
B0000h
1
0
1
1
External bus, J7
D0000h
1
1
0
1
CS0
User-installed Flash, U24
40000h
0
1
0
0
User-installed Flash, U27
50000h
0
1
0
1
Caution: