r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 276

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller (BSC)
Commands that are supported by this LSI are NOP, auto-refresh (REF), self-refresh (SELF), all
bank precharge (PALL), row address strobe bank-active (ACTV), read (READ), write (WRIT),
and mode-register write (MRS). Commands for bank control cannot be used.
6.8.2
With continuous synchronous 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. The address-precharge-setting command (Precharge-sel) can be output on
the upper column address. Table 6.9 shows the relation between the settings of MXC2 to MXC0
and the shift size. The MXC2 bit should be set to 1 when the synchronous DRAM interface is
used.
Table 6.9
Legend:
×: Don’t care.
P: Precharge-sel
Rev. 1.00 Sep. 19, 2008 Page 246 of 1342
REJ09B0467-0100
Row
address
Column
address
MXC2
Address Multiplexing
0
1
0
1
DRAMCR
Relation between Settings of Bits MXC2 to MXC0 and Address Multiplexing
MXC1
×
0
1
×
0
1
MXC0
×
0
1
0
1
×
0
1
0
1
Shift
Size
8
bits
9
bits
10
bits
11
bits




A23 to
A16
A23 to
A16
A23 to
A16
A23 to
A16
A23 to
A16
A23 to
A16
A23 to
A16
A23 to
A16
A23 to
A16
A15 A14 A13 A12 A11 A10 A9
A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10
A15 A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9
A15 A14 A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10
A15 A14 A13 A23 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13 A12 A11
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
Reserved (setting prohibited)
Reserved (setting prohibited)
A11 A10
P
P
P
A10
P
P
Address Pins
A9
A9
A9
P
A8
A8
A8
A8
A8
A7
A7
A7
A7
A7
A6
A6
A6
A6
A6
A5
A5
A5
A5
A5
A4
A4
A4
A4
A4
A3
A3
A3
A3
A3
A2
A2
A2
A2
A2
A1
A9
A1
A1
A1
A1
A0
A8
A0
A0
A0
A0