upd78f0148m1gka1-9eu Renesas Electronics Corporation., upd78f0148m1gka1-9eu Datasheet - Page 121

• Manufacturer Part Number: upd78f0148m1gka1-9eu
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.2
Address: FF47H
Symbol
The external bus interface is controlled by the following two registers.
• Memory expansion mode register (MEM)
• Memory expansion wait setting register (MM)
(1) Memory expansion mode register (MEM)
MEM
Registers Controlling External Bus Interface
MEM sets the external expansion area.
MEM is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears MEM to 00H.
MM2
7
0
0
0
1
1
1
Other than above
After reset: 00H
Figure 5-2. Format of Memory Expansion Mode Register (MEM)
MM1
6
0
0
1
0
0
1
MM0
CHAPTER 5 EXTERNAL BUS INTERFACE
5
0
0
1
0
1
1
R/W
expansion mode selection P40 to P47 P50 to P53 P54, P55
Single-chip mode
Memory
expansion
mode
Setting prohibited
User’s Manual U15947EJ3V1UD
Single-chip/memory
4
0
Note
256-byte
mode
4 KB
mode
16 KB
mode
Full-address
mode
3
0
Port mode
AD0 to
AD7
MM2
2
P40 to P47, P50 to P57, P64 to P67 pin state
Port mode
A8 to A11
MM1
1
Port mode
A12, A13
MM0
0
Port mode
A14, A15
P56, P57 P64 to P67
P64 = RD
P65 = WR
P66 = WAIT
P67 = ASTB
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