Datasheet

Section 6 Bus Controller (BSC)
Page 224 of 1408 R01UH0309EJ0500 Rev. 5.00
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
6.7.2 Address Multiplexing
With DRAM space, the row address and column address are multiplexed. In address multiplexing,
the size of the shift of the row address is selected with bits MXC2 to MXC0 in DRAMCR. Table
6.6 shows the relation between the settings of MXC2 to MXC0 and the shift size.
The MXC2 bit should be cleared to 0 when the DRAM interface is used.
Table 6.6 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 A8 0
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 × × Reserved (setting prohibited)
0 × × ⎯ A23
to
A16
A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Column
address
1 × × Reserved (setting prohibited)
[Legend]
×: Don't care.