S3C2416X RISC MICROPROCESSOR
SYSTEM
CONTROLLER
2-1
2
SYSTEM CONTROLLER
1 OVERVIEW
The system controller consists of three parts; reset control, system clock control, and system power-management
control. The system clock control logic in S3C2461 can generate the required system clock signals which are the
inputs of ARM926EJ, several AHB blocks, and APB blocks. There are two PLLs in S3C2416 to generate internal
clocks. One is for general functional blocks, which include ARM, AHB, and APB. The other is for the special
functional clocks which are the USB, I2S and camera interface clock. Software program control the operating
frequency of the PLLs, internal clock sources and enabled or disabled the clocks to reduce the power
consumption.
S3C2416 has various power-down modes to keep optimal power consumption for a given task. The power-down
modes consists of four modes; NORMAL mode, IDLE mode, STOP mode, and SLEEP mode. In NORMAL mode,
the input clock of each block is enabled or disabled according to the software to eliminate the power consumption
of unused blocks for a certain application. For example, if an UART is not needed, the software can disable the
input clock independently. The major power dissipation of S3C2416 is due to ARM core, since the operating
speed is relative higher than that of the other blocks. Typically, the operating frequency of the ARM core is
400MHz, while the AHB blocks and the APB blocks operate on 133MHz and 66MHz, respectively. Thus, the
power control of the ARM core is major issue to reduce the overall power dissipation in S3C2416, and IDLE mode
is supported for this purpose. In IDLE mode, the ARM core is not operated until the external interrupts or internal
interrupts. The STOP mode freezes all clocks to all peripherals as well as the ARM core by disabling PLLs. The
power consumption is only due to the leakage current and the minimized alive block in S3C2416. SLEEP mode is
intended to disconnect the internal power. So, the power consumption due to the ARM core and the internal logic
except the wake-up logic will be nearly zero in the SLEEP mode. In order to use the SLEEP mode two
indenpendent power sources are required. One of the two power soruces supplies the power for the wake-up
logic. The other one supplies the normal functional blocks including the ARM core. It should be controlled in order
to turn ON/OFF with a special pin in S3C2416. The detailed description of the power-saving modes such as the
entering sequence to the specific power-down mode or the wake-up sequence from a power-down mode is given
in the following Power Management section.
2 FEATURE
•
Include two on-chip PLLs called main PLL(MPLL), extra PLL(EPLL)
•
MPLL generates the system reference clock
•
EPLL generates the clocks for the special functional blocks
•
Independent clock ON/OFF control to reduce power consumption
•
Support three power-down modes, IDLE, STOP, and SLEEP, to optimize the power dissipation
•
Wake-up by one of external Interrupt, RTC alarm, Tick interrupt and BATT_FLT.(Stop and Sleep mode)
•
Control internal bus arbitration priority
Summary of Contents for S3C2416
Page 122: ...BUS MATRIX EBI S3C2416X RISC MICROPROCESSOR 3 4 NOTES ...
Page 204: ...DMA CONTROLLER S3C2416X RISC MICROPROCESSOR 8 18 NOTES ...
Page 284: ...WATCHDOG TIMER S3C2416X RISC MICROPROCESSOR 11 6 NOTES ...
Page 320: ...REAL TIME CLOCK S3C2416X RISC MICROPROCESSOR 13 16 NOTES ...
Page 344: ...UART S3C2416X RISC MICROPROCESSOR 14 24 NOTES ...
Page 380: ...USB2 0 DEVICE S3C2416X RISC MICROPROCESSOR 16 34 NOTES ...
Page 432: ...2D S3C2416X RISC MICROPROCESSOR 18 38 NOTES ...
Page 446: ...HS_SPI CONTROLLER S3C2416X RISC MICROPROCESSOR 19 14 NOTES ...
Page 604: ...S3C2416X RISC MICROPROCESSOR S3C2416X RISC MICROPROCESSOR 23 22 NOTES ...
Page 638: ...PCM AUDIO INTERFACE S3C2416X RISC MICROPROCESSOR 25 18 NOTES ...
Page 670: ...ELECTRICAL DATA S3C2416X RISC MICROPROCESSOR 26 32 NOTES ...