
iiBusModuLes:sRaMContRoLLeR(sRaMC)
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ii-3-9
II
SRAMC
ii.3.5sRaMCoperatingClockandBusClock
ii.3.5.1operatingClockofthesRaMC
The SRAMC is clocked by the SRAMC_CLK and SRAMC_SAPB_CLK clocks (= MCLK) generated by the CMU.
The bus control signals are generated synchronously with SRAMC_CLK.
The SRAMC_SAPB_CLK is used for the SRAMC control registers.
For details on how to set and control the SRAMC operating clocks, see Section III.1, “Clock Management Unit
(CMU).”
ControllingsupplyofthesRaMCoperatingclock
The SRAMC operating clocks are supplied to the SRAMC with default settings. Each clock supply can be
controlled in the CMU. Use the respective control bits to turn off any unnecessary clock supplies to reduce the
amount of power consumed on the chip.
1.sRaMC_saPB_CLK
The SRAMC_SAPB_CLK is used to operate the SRAMC control registers. To setup the registers, this clock
is required. After the registers are set up, the clock supply can be stopped to reduce power consumption by
setting SRAMSAPB_CKE (D7/0x301B04) to 0.
sRaMsaPB_CKe:SRAMCSAPBI/FClockControlBitintheGatedClockControlRegister1
(D7/0x301B04)
2.sRaMC_CLK
The SRAMC_CLK is used for the SRAM interface. To access the external memories/devices and the
peripheral control registers in area 6, this clock is required. So this clock cannot be stopped in normal
operation mode. However, the clock supply can be stopped in HALT mode. By setting SRAMC_HCKE
(D26/0x301B04) to 0, the SRAMC_CLK stops when the CPU enters HALT mode and it resumes when the
CPU exits HALT mode.
sRaMC_hCKe:SRAMCClockControl(HALT)BitintheGatedClockControlRegister1(D26/0x301B04)
Clockstateinstandbymode
The supply of the SRAMC operating clock stops depending on the type of standby mode.
HALT mode: The operating clock is supplied the same way as in normal mode.
It can be stopped by setting the CMU register.
SLEEP mode: The clock supply stops.
Therefore, the SRAMC also stops operating in SLEEP mode.