SYSTEM CONTROLLER
S3C2416X RISC MICROPROCESSOR
2-8
5.3 PLL
(PHASE-LOCKED-LOOP)
The PLL (Phase-Locked Loop) frequency synthesizer is constructed in CMOS on single monolithic structure. The
PLL provides frequency multiplication capabilities.
MPLL generates the clock sources for ARMCLK, HCLK, PCLK, DDRCLK and SSMCCLK and EPLL generates
clock sources for USBHOSTCLK, CAMCLK and so forth.
The following sections describe the operation of the PLL, that includes the phase difference detector, charge
pump, VCO (Voltage controlled oscillator), and loop filter.
Refer to MPLLCON and EPLLCON registers to change PLL output frequency.
Fout
Off-chip loop filter
Fin
Pre-Divider
Main
Divider
PFD
Charge
Pump
VCO
Post
Scaler
Figure 2-5. PLL(Phase-Locked Loop) Block Diagram
5.4 CHANGE PLL SETTINGS IN NORMAL OPERATION
During the operation of S3C2416 in NORMAL mode, if the user wants to change the frequency by writing the PMS
value, the PLL lock time is automatically inserted. During the lock time, the clock is not supplied to the internal
blocks in S3C2416. The timing diagram is as follow.
MPLL_clk
PMS setting
PLL Locktime
SYSCLK
It changes to new PLL clock
after lock time automatically
It changes to LOW value during
lock time automatically
Figure 2-6. The Case that Changes Slow Clock by Setting PMS Value
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 ...