pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 238

• Manufacturer Part Number: pc87591l
• Description: Lpc Mobile Embedded Controllers
• Manufacturer: National Semiconductor Corporation

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Embedded Controller Modules
4.17.5 Usage Hints
The hints below apply when Idle mode is used with a disabled HFCG.
1. When disabling HFCG in Idle mode, on wake-up, a frequency clock may be generated that differs from the selected set-
2. After waking up from Idle mode, wait 0.5 seconds before returning to the optimal SZCFG0 configuration.
ting due to temperature variations in the working environment during the idle period. For details on the resulting deviation
from the nominal frequency, refer to “tCLKINTwk” on page 385. To avoid any failures that may result from waking up to
a higher frequency in case the access time to the internal or external memory is marginal using the current BIU config-
uration, follow the procedures exactly.
Before entering Idle mode, configure SZCFGi (where i=0-2) for an additional Wait clock cycle (see Section 4.1.10 on
page 83 for details on SZCFGi configuration).
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