m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 70

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

Fig. 4.2.4 Structure of particular function select register 0
4.2.3 Particular function select register 0
Figure 4.2.4 shows the structure of the particular function select register 0, and Figure 4.2.5 shows the
writing procedure for the particular function select register 0.
Particular function select register 0
Note: Writing to these bits requires the following procedure:
7 to 2
Bit
0
1
• Write “55
• Succeedingly, write “0” or “1” to each bit.
Also, use the MOVMB (MOVM when m = 1) instruction or STAB (STA when m = 1) instruction.
If an interrupt occurs between writing of “55
possibility that an interrupt occurs at the above timing, be sure to read this bit’s contents after writing of “0” or “1,” and verify
whether “0” or “1” has correctly been written or not.
STP instruction invalidity select bit
External clcok input select bit
Fix this bit to “0.”
16
” to this register. (The bit status does not change only by this writing.)
Bit name
(Address 62
7905 Group User’s Manual Rev.1.0
0 : STP instruction is valid.
1 : STP instruction is invalid.
0 : Oscillation circuit is active. (Oscillator is connected.)
1 : Oscillation circuit is inactive. (External clock is
16
” and next writing of “0” or “1,” latter writing may be ignored. When there is a
Watchdog timer is used at stop mode termination.
When the system clock select bit (bit 5 at address BC
watchdog timer is not used at stop mode termination.
When the system clock select bit = “1,”
watchdog timer is used at stop mode termination.
input.)
CLOCK GENERATING CIRCUIT
16
)
Function
b7 b6 b5 b4 b3 b2 b1 b0
0
16
0
) = “0,”
0
0
At reset
0 0
0
0
0
4.2 Clocks
(Note)
(Note)
R/W
RW
RW
RW
4-9