Datasheet

Section 6 Bus Controller (BSC)
Rev. 3.00 Mar 17, 2006 page 174 of 926
REJ09B0283-0300
Table 6.5 Relation between Settings of Bits MXC2 to MXC0 and Address Multiplexing
DRAMCR Address Pins
MXC2 MXC1 MXC0
Shift
Size
A23
to
A16
A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
0 8 bits
A23
to
A16
A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9 A80
1 9 bits A23
to
A16
A15 A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9
0 10 bits
A23
to
A16
A15 A14 A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10
0
1
1 11 bits A23
to
A16
A15 A14 A13 A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11
Row
address
1
xx Reserved (setting prohibited)
0
*
xx — A23
to
A16
A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0Column
address
1
*
xx Reserved (setting prohibited)
Legend: x: Don’t care
Note: * In the H8S/2678 Group, address pins are A23 to A0.
6.6.3 Data Bus
If a bit in ABWCR corresponding to an area designated as DRAM space is set to 1, that area is
designated as 8-bit DRAM space; if the bit is cleared to 0, the area is designated as 16-bit DRAM
space. In 16-bit DRAM space, ×16-bit configuration DRAM can be connected directly.
In 8-bit DRAM space the upper half of the data bus, D15 to D8, is enabled, while in 16-bit DRAM
space both the upper and lower halves of the data bus, D15 to D0, are enabled.
Access sizes and data alignment are the same as for the basic bus interface: see section 6.5.1, Data
Size and Data Alignment.