HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 184

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

Example 4: Connection to Multiple 4-Mbit DRAM Chips (16-Mbyte Mode): Figure 7-13
shows an example of interconnections to two 2CAS 4-Mbit DRAM chips, and the corresponding
address map. Up to four DRAM chips can be connected to area 3 by decoding upper address bits
A
Figure 7-14 shows a setup procedure to be followed by a program for this example. The DRAM
in this example has 9-bit row addresses and 9-bit column addresses. Both chips must be refreshed
simultaneously, so the RFSH pin must be used.
19
Figure 7-13 Interconnections and Address Map for Multiple 2CAS 4-Mbit DRAM Chips
and A
20
.
H8/3048 Series
H'600000
H'67FFFF
H'680000
H'6FFFFF
H'700000
H'7FFFFF
D
A to A
15
9
RFSH
HWR
to D
LWR
CS
A
RD
19
1
3
0
DRAM area
DRAM area
Not used
No. 1
No. 2
a. Interconnections (example)
b. Address map
(Example)
170
Area 3 (16-Mbyte mode)
2
row address, 9-bit column
address, and
CAS
A to A
RAS
UCAS
LCAS
WE
OE
I/O
A to A
RAS
UCAS
LCAS
WE
OE
I/O
8
8
15
15
4-Mbit DRAM with 9-bit
to I/O
to I/O
0
0
0
0
16-bit organization
No. 1
No. 2