GMS30C7201 Datasheet, PDF (58/352 Pages) Hynix Semiconductor – 60MHz operation frequency Low power consumption

PMU & PLL
7.1 Overview
The GMS30C7201 is designed primarily for HPC and other portable computing applications.
Therefore there are 4 operating modes to reduce power consumption and extend battery life.
• RUN - normal operation (typically used when softmodem is in operation and other
CPU-intensive tasks)
• SLOW - half-speed operation used when the application interacts with a user (e.g.
word processing)
• IDLE - where the CPU operation is halted but peripherals operation continue (such as
screen refresh, or serial communications)
• SLEEP & DEEP SLEEP - This mode will be perceived as ‘off’ by the user, i.e. the
contents of SDRAM are maintained and only the real-time clock is running.
There are a number of Power management states, (see 7.3 Power management states on page
7-5) as described above, and the transition between states is controlled by the PMU. The PMU
is an ASB slave unit to allow the CPU to write to its control registers, and is an ASB master unit
to provide the mechanism for stopping the ARM core’s internal clock).
7-2
GMS30C7201 Data Sheet