Kontron VMOD-2D - Manual (Page 29)

VMOD-2/VMOD-2D
12/15/97
Functional Description
Page 2 - 3 Man. ID 03139, Rev. Index 0200
Addressing piggyback (i.e. PB-REL) fitted in location A (the upper position on VMOD-2)
• VMOD-2 BASE ADDRESS+$41= PB-REL's ID Vector (read only)
• VMOD-2 BASE ADDRESS+$01= PB-REL's 8-bit output port Register
(read/write)
Addressing piggyback (i.e. PB-REL) fitted in location B (the lower position on VMOD-2)
• VMOD-2 BASE ADDRESS+$C1/$1041* = PB-REL's ID Vector (read
only)
• VMOD-2 BASE ADDRESS+$81/$1001* = PB-REL's 8-bit output port
Register (read/write)
* Actual offset for lower piggyback is subject to the setting of jumper B16 and could be $10xx
if a 5230-xx piggyback is fitted into the upper piggyback location, and jumper B16 is set. I.e. 8
KByte address width is required.
A jumper set results in the related address line being assigned a logical low (0) function.
2.1.1 Selection of Address Block Widths
As mentioned in the preceding section, an important aspect regarding the use of the VMOD-2
is the option of block size selection, which must be taken into consideration when using the
VMOD-2 in certain configurations and/or applications.
When using the VMOD-2 to replace an existing VMOD (as a one-to-one direct replacement),
the VMOD-2 should be set to the narrower address range of 256 Bytes by opening the jumper
B16. This ensures that the VMOD-2 presents an address width of only 256 Bytes identical to
the old VMOD, and uses offsets of $01 and $80 for the two piggyback locations.
No new "5230-xx" piggybacks should be added to the VMOD-2 when used as a replacement
for an older VMOD since when jumper B16 is open the enhanced (5230-xx) piggybacks will
not have the use of additional address lines A7...A11 and will not therefore function correctly.
Where using existing piggybacks and a VMOD-2 to substitute an older style VMOD, we rec-
Table 2-1: Default Setting of the VMOD-2 Base Address
Configuration for base address range $FE2400 to $FE24FF
VMOD-2 Jumpers B02 B12 B13 B14 B15 B16 Base Address
Default Settings Set Set Open Set Set Open $FE2400
Address Lines A15 A14 A13 A12 A11 in
256
Byte
block