Rom - Samsung S5PC110 Manual

S5PC110_UM

4.8.2 ROM

ROM has three power modes, namely, Run, Stand-by, and Power-down mode.
•
In Run mode, read access to ROM can be performed normally.
•
In Stand-by mode, chip selection to ROM is deactivated, so that there is no read access.
•
In Power-down mode, all power to core and peripheral circuitry is off internally.
In NORMAL mode, all three power modes can be used.
When ROM is in use, two power modes are available. Run mode is used when there is read access, while
Standby mode is used when there is no read access. The decision to move from one mode to another is made by
the internal ROM controller.
If ROM is not in use, then it can enter into Power-down mode. Set the IROM field of NORMAL_CFG register in
SYSCON for Entry to, and exit from Power-down mode.
In IDLE mode, and DEEP-IDLE mode where TOP block is "ON", ROM keeps its operation or power state in
NORMAL.
In DEEP-IDLE mode where TOP block is "OFF", STOP mode and DEEP-STOP mode, ROM can have two power
states. If IROM bit of NORMAL_CFG is 1'b1, then ROM keeps stand-by mode. Otherwise, ROM keeps power
down mode.
In SLEEP mode, power to ROM is "OFF", so the data in ROM will be lost. Power mode in SLEEP mode has no
meaning.
4 POWER MANAGEMENT
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