HD404449 Datasheet, PDF (35/125 Pages) Hitachi Semiconductor – HD404449 SERIES

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
HD404449 Series
MIS3 MIS2
Buffer control.
Refer to figure 38.
MIS1
0
0
1
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 Ceramic oscillator or crystal
125 ms
62.5 ms
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:
• Set LSON to 0 and DTON to 1 in subactive mode.
• Execute the STOP or SBY instruction.
• The MCU automatically enters active mode from subactive mode after waiting for the MCU internal
processing time and oscillation stabilization time (Figure 19).
Notes: 1. The DTON flag ($020, bit 3) can be set only in subactive mode. It is always reset in active
mode.
2. The transition time (T_D) from subactive mode to active mode:
t_RC < T_D < T + t_RC
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