Motorola MVME2300 Series - Manual (Page 211)

Programming Model
http://www.motorola.com/computer/literature 3-49
3
rom_b_64 matches the inverse of the value that was on the
CKD3 pin at power-up reset. It cannot be changed by
software.
rom b siz The rom b siz control bits are the size of ROM/Flash for
block B. They are encoded as shown in
Table 3-17 .
Table 3-17. ROM Block B Size Encoding
rom_b_rv rom_b_rv and rom_a_rv determine which if either of
Blocks A and B is the source of reset vectors or any other
access in the range $FFF00000 - $FFFFFFFF as shown in
Table 3-15 .
rom_b_rv is initialized at power-up reset to match the
inverse of the value on the CKD1 pin.
rom b en When rom b en is set, accesses to block B ROM/Flash in
the address range selected by ROM B BASE are enabled.
When rom b en is cleared they are disabled.
rom b we When rom b we is set, writes to block B ROM/Flash are
enabled. When rom b we is cleared they are disabled.
Refer back to
Table 3-16 for more details.
rom b siz Block Size
%000 1MB
%001 2MB
%010 4MB
%011 8MB
%100 16MB
%101 32MB
%110 64MB
%111 Reserved