
15
15-15
32170/32174 Group User's Manual (Rev. 2.1)
Figure 15.4.2 Typical Connection of External Extension Memory (When BUSMOD = 1)
Note: The 32170 addresses and data are arranged in such a way that bit 0 = MSB, and bit 15 =
LSB. Therefore, the MSB and LSB sides must be reversed when connecting external
extension memory.
EXTERNAL BUS INTERFACE
15.4 Typical Connection of External Extension Memory
(2) When Bus Mode Control Register = 1
A typical connection when using external extension memory is shown in Figure 15.4.2. (External
extension memory can only be used in external extension mode and processor mode.)
M32170F6
A11
A30
D0
D15
RD
CS0
CS1
BLE
BHE
WAIT
H’0000 0000
H’0040 0000
H’0020 0000
H’000C 0000
H’0010 0000
A18
A0
D15
D0
RD
CS
max1MB
A19
A0
D15
D0
RD (D0-D15)
CS
BHE (D0-D7)
BLE (D8-D15)
max2MB
WR
WR (D0-D15)
Memory mapping
Internal flash memory
(768KB)
External
memory area
(1MB)
Number of bus wait cycles can be set to 1-4.
Normally used as port. WAIT is used only when four or more wait cycles are needed.
Unused
1M-CS0 area
SRAM
Flash memory
External
memory area
(2MB)
2M-CS1 area