m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 43

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

CENTRAL PROCESSING UNIT (CPU)
2.5 Processor modes
Fig. 2.5.3 Structure of processor mode register 0
2-20
2.5.2 Setting of processor mode
The processor mode is set by the following:
• Voltage level applied to the MD0 and MD1 pins
• Processor mode bits (bits 1 and 0 at address 5E
The V
the single-chip mode. Also, the processor mode bit must be “00.”
Figure 2.5.2 shows the structure of the processor mode register 0 (address 5E
Processor mode register 0
X : It may be either “0” or “1.”
SS
Bit
0
1
2
3
4
5
6
7
–level voltage must be applied to the MD0 and MD1 pins, because the M37905 operates only in
Processor mode bits
Any of these bits may be either “0” or “1.”
Interrupt priority detection time
select bits
Software reset bit
Fix this bit to “0.”
Bit name
(Address 5E
7905 Group User’s Manual Rev.1.0
16
b5 b4
)
b1 b0
0 0 : 7 cycles of f
0 1 : 4 cycles of f
1 0 : 2 cycles of f
1 1 : Do not select.
The microcomputer is reset by writing “1” to this
bit. The value is “0” at reading.
0 0 : Single-chip mode
0 1 : Do not select.
1 0 : Do not select.
1 1 : Do not select.
16
)
sys
sys
sys
Function
b7 b6 b5 b4 b3 b2 b1 b0
0
16
).
At reset
X X 0 0
0
0
0
1
0
0
0
0
R/W
WO
RW
RW
RW
RW
RW
RW
RW