
5-9
ML63326 User's Manual
Chapter 5 Clock Generator Circuit (OSC)
5
When ENOSC (bit 1 of FCON) is set to "1", the voltage doubler circuit that doubles V
DD2
starts
operating and outputs the power supply voltage (V
DDH
) for high speed oscillation. The
oscillations are started in the mode set by OSCSEL. At the same time, the internal logic power
supply voltage (V
DDL
) switches from the constant voltage circuit output level (approx. 1.7 V)
to the V
DDH
level. Next, if CPUCLK is set to "1", the system clock switches from crystal
oscillation output (TBCCLK) to high-speed clock output (HSCLK).
Figure 5-4 shows the system clock select timing and status of the power supply voltage for
high-speed oscillation (V
DDH
) and the internal logic power supply voltage (V
DDL
).
ENOSC
CPUCLK
System clock
T
WAIT
High-speed clock
Low-speed clock
0.5 to 2.0 high-speed clocks
0.5 to 1.0 low-speed clocks
Internal logic
power supply voltage
(V
DDL
)
V
DD
V
SS
= 0 V
Approx. 1.7 V
(typ.)
Low-speed clock
OSC1
Power supply voltage for
high-speed oscillation
(V
DDH
)
2
¥
V
DD2
V
SS
= 0 V
Figure 5-4 System Clock Select Timing
In the crystal oscillation mode, 10 ms are required from the time when ENOSC is set to "1"
until the high-speed clock generator circuit enters the oscillating state. Therefore, in this
mode, when switching CPUCLK to a high-speed setting, wait for an interval of at least T
WAIT
= 10 ms after the rising edge of ENOSC.
In the CR oscillation mode, oscillation begins soon after setting ENOSC to "1". However, it
takes about 5 ms for the power supply voltage for high-speed oscillation (V
DDH
) to stabilize.
Therefore, when switching CPUCLK to a high-speed setting, wait for an interval of at least
T
WAIT
= 5 ms after the rising edge of ENOSC.
When switching from the high-speed mode to the low-speed mode, set the CPUCLK bit to "0",
and sometime after the next instruction, set the ENOSC bit to "0".
For details regarding the power supply for high-speed oscillation and the constant voltage
circuit for the internal logic power supply, refer to Chapter 17, "Power Supply Circuit."
Summary of Contents for ML63326
Page 3: ......
Page 13: ......
Page 14: ...Chapter 1 Overview 1 ...
Page 15: ......
Page 37: ...1 22 ML63326 User s Manual Chapter 1 Overview ...
Page 38: ...Chapter 2 CPU and Memory Spaces 2 ...
Page 39: ......
Page 50: ...CPU Control Functions Chapter 3 3 ...
Page 51: ......
Page 57: ...3 6 ML63326 User s Manual Chapter 3 CPU Control Functions ...
Page 58: ...Interrupt INT326 Chapter 4 4 ...
Page 59: ......
Page 71: ...4 12 ML63326 User s Manual Chapter 4 Interrupt INT326 ...
Page 72: ...Clock Generator Circuit OSC Chapter 5 5 ...
Page 73: ......
Page 83: ...5 10 ML63326 User s Manual Chapter 5 Clock Generator Circuit OSC ...
Page 84: ...Time Base Counter TBC Chapter 6 6 ...
Page 85: ......
Page 90: ...Timers TIMER Chapter 7 7 ...
Page 91: ......
Page 115: ...7 24 ML63326 User s Manual Chapter 7 Timers TIMER ...
Page 116: ...Chapter 8 8 100 Hz Timer Counter 100HzTC ...
Page 117: ......
Page 121: ...8 4 ML63326 User s Manual Chapter 8 100 Hz Timer Counter 100HzTC ...
Page 122: ...Chapter 9 9 Watchdog Timer WDT ...
Page 123: ......
Page 128: ...Chapter 10 10 Ports INPUT OUTPUT I O PORT ...
Page 129: ......
Page 170: ...Chapter 11 11 External Memory Transfer Function EXTMEM ...
Page 171: ......
Page 179: ...11 8 ML63326 User s Manual Chapter 11 External Memory Transfer Function EXTMEM ...
Page 180: ...Chapter 12 12 Melody Driver MELODY63K ...
Page 181: ......
Page 195: ...12 14 ML63326 User s Manual Chapter 12 Melody Driver MELODY63K ...
Page 196: ...13 Chapter 13 Voice Synthesis ...
Page 197: ......
Page 228: ...14 Chapter 14 Shift Register SFT ...
Page 229: ......
Page 236: ...15 Chapter 15 LCD Driver LCD ...
Page 237: ......
Page 250: ...16 Chapter 16 Battery Low Detect Circuit BLD ...
Page 251: ......
Page 255: ...16 4 ML63326 User s Manual Chapter 16 Battery Low Detect Circuit BLD ...
Page 256: ...Chapter 17 17 Power Supply Circuit POWER ...
Page 257: ......
Page 260: ...Appendixes ...
Page 261: ......
Page 321: ...Appendix 60 ML63326 User s Manual Appendix G ...