Samsung S5PC110, Manual

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S5PC110_UM 4 POWER MANAGEMENT
4-8
There are two wakeup techniques. First technique is applied to TOP domain and System Timer domain, whereas
the other is applied to SUB domains (except System Timer domain).
The first technique is as follows:
The logic gates in TOP and System Timer domains are turned “ON” in two steps, and then memories are turned
“ON” one-by-one in memory group. Two steps means that about 10% of all switches are supplied power first, and
the remaining 90% switches are supplied power after some time. The power-up time is composed of the logic
power-up time and the memory power-up time. These are determined by the oscillator frequency, number of
memories and count values given in the OSC_FREQ registers. The count value depends on the size of the logic
gates and number of memories. System Timer domain has no memory, and therefore memory power-up time is
not necessary.
The second technique is as follows:
The logic gates and memory in SUB domains (except System Timer domain) are turned “ON” at the same time.
However, to prevent wakeup noise from occurring, the power to switches is supplied in two steps similar with first
technique. About 10% switches are supplied power first, and remaining 90% switches are supplied power after
some time.