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PRELIMINARY
S3C6400X RISC MICROPROCESSOR
SYSTEM CONTROLLER
3-5
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
Main-Divider
(M)
M[9:0]
P[5:0]
Phase
Frequency
Detector
Charge
Pump
Voltage
Controlled
Oscillator
FIN
PWRDN
AVDD10D
AVSS10D
Vctrl
UP
DN
Fvco
Fvco / M
AVDD10A
AVBBA
AVSS10A
M[9:0]
R1
C2
Scaler
(S)
FOUT
Pre-Divider
(P)
Fin / P
P[5:0]
S[2:0]
S[2:0]
AVBBD
C1
DVSS10D
Figure 3-3. PLL block diagram (APLL, MPLL only)
Clock selection between PLL’s and input reference clock
Figure 3-4 shows the clock generation logic. S3C6400X has three PLL’s which are APLL for ARM operating clock,
MPLL for main operating clock, and EPLL for special purpose. The operating clocks are divided into three groups.
The first is ARM clock, which is generated from APLL. MPLL generates the main system clocks, which are used
for operating AXI, AHB, and APB bus operation. The last group is generated from EPLL. Mainly, the generated
clocks are used for peripheral IP’s, i.e., UART, IIS, IIC, and etc.
Figure 3-4. Clock generation from PLL outputs