MITSUBISHI MICROCOMPUTERS
7470/7471 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
<An example of flow for system>
Power on reset
↓
Clock X oscillation
↓
Internal system clock start (X→1/2→ φ)
↓
Program start from RESET vector
Normal program ← Operating at f(XIN)
Clock for clock function XC oscillation start (CM4 = 1, CM5 = 1)
↓
Latency time for oscillation to stabilize (by program) ← Operating at f(XIN)
↓
XC clock power down (CM5 : 1→0)
↓
Internal clock φ source switching X→XC (CM7 : 0→1)
↓
Clock X halt (XC in operation) (CM6 = 1)
↓
Internal clock halt (WIT instruction)
↓
Timer 4 (clock count) overflow
↓
Internal clock operation start (WIT instruction released)
Clock processing routine
← Operating at f(XCIN)
Internal clock halt (WIT instruction)
Interrupts from INT0, INT1, CNTR0/CNTR1, timer 1, timer 2, timer 3, timer 4, serial I/O, key on wake up
↓
Internal clock operation start (WIT instruction released)
↓
Program start from interrupt vector
↓
Clock X oscillation start (CM6 = 0)
↓
Latency time for oscillation to stabilize (by program)
← Operating at f(XCIN)
↓
Internal clock φ source switching (XC→X) (CM7 : 1→0)
Normal program → Operating at f(XIN)
32
ETC [ ETC ]
