HD404459 Datasheet, PDF (35/122 Pages) Renesas Technology Corp – 4-bit HMCS400-series microcomputers

Miscellaneous register (MIS: $00C)
Bit
Initial value
Read/Write
Bit name
3
0
W
MIS3
2
0
W
MIS2
1
0
W
MIS1
0
0
W
MIS0
HD404459 Series
MIS3 MIS2
Buffer control.
Refer to figure 39.
MIS1
0
1
MIS0
0
1
0
1
T ^*1
t_RC^*1
Oscillation circuit conditions
0.24414 ms 0.12207 ms External clock input
0.24414 ms^*2
15.625 ms 7.8125 ms
125 ms
62.5 ms
Ceramic or crystal oscillator
Not used
—
Notes: 1. The values of T and t_RC are applied when a 32.768-kHz crystal oscillator is used.
2. The value is applied only when direct transfer operation is used.
Figure 18 Miscellaneous Register (MIS)
Direct Transition from Subactive Mode to Active Mode: Available by controlling the direct transfer on
flag (DTON: $020, bit 3) and the low speed on flag (LSON: $020, bit 0). The procedures are described
below:
1. Set LSON to 0 and DTON to 1 in subactive mode.
2. Execute the STOP or SBY instruction.
3. The MCU automatically enters active mode from subactive mode after waiting for the MCU internal
processing time and oscillation stabilization time (figure 19).
Notes: The DTON flag ($020, bit 3) can be set only in subactive mode. It is always reset in active mode.
The transition time (T_D) from subactive mode to active mode is:
t_RC < T_D < T + t_RC
33