Samsung S5PC100, User Manual, Page: 221 / 1863

Power Management S5PC100 USER’S MANUAL (REV1.0)
2.4-22
6.1 SRAM
SRAM in Top domain has four power modes: Run, Stand-by, Retention, and Power-down mode.
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In Run mode, read and write access to SRAM are performed normally.
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In Stand-by mode, SRAM chip select is deactivated, so that there is no read and write access.
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In Retention mode, power is provided to only core of SRAM, and power to peripheral circuitry is off internally.
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In Power-down mode, all power to core and peripheral circuitry is off.
The list of SRAM in Top domain is as follows: CCAN, IRDA, MODEM IF, USB_OTG, SDMMC, CSSYS, SECSS,
internal RAM 0, 1, and 2. (Refer to STOP_MEM_CFG register in Section 10 REGISTER DESCRIPTION)
In NORMAL mode, run, or stand-by mode is used.
Run mode is used if there is read and write access, while stand-by mode is used if there is no read and write
access. The change between these two modes is done by corresponding SRAM control logic.
In IDLE mode, and DEEP-IDLE mode (top domain on), SRAM keeps its operation or power state in NORMAL.
In DEEP-IDLE mode (top domain is off), SRAM in TOP module enters stand-by, retention, or power-down mode.
Before entry to this mode, you must set the TOP_MEMORY_ON_DIDLE and TOP_MEMORY_RET_ON_DIDLE
field PWR_CFG in PMU.
In STOP mode and DEEP-STOP mode, stand-by, retention, and power-down mode can be entered.
Before entry to STOP mode, you must set the TOP_MEMORY_ON and TOP_MEMORY_RET field of STOP_CFG
register in PMU to determine which power mode SRAM enters during STOP mode. And each SRAM can be
separately set in STOP_MEM_CFG register.
In SLEEP mode, power to SRAM is off, so the data in SRAM is lost. Power mode of SRAM in SLEEP mode has
no meaning.
6.2 ROM
ROM has two power modes: Run, and Stand-by mode.
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In Run mode, read access to ROM is performed normally.
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In Stand-by mode, chip selection to ROM is deactivated, so that there is no read access.
In NORMAL mode, both power modes are used. Run mode is used if there is read access, while Standby-mode is
used if there is no read access. The change between these two modes is done by ROM control logic.
In IDLE mode and DEEP-IDLE mode (top domain on), ROM keeps its operation or power state in NORMAL.
To enter DEEP-IDLE mode (top domain is off), STOP mode and DEEP-STOP mode, s/w should not access ROM
so that ROM enter Stand-by mode.
In SLEEP mode, power to ROM is off. Power mode of ROM in SLEEP mode has no meaning.