SC1200UCL-266 AMD (ADVANCED MICRO DEVICES), SC1200UCL-266 Datasheet - Page 332

• Manufacturer Part Number: SC1200UCL-266
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of SC1200UCL-266

• Lead Free Status / Rohs Status: Not Compliant

7.2.8
The integrated (CRT) PLL can generate frequencies up to
135 MHz from a single 27 MHz source. The clock fre-
quency is programmable using two registers. Figure 7-16
shows the block diagram of the Video Processor integrated
PLL.
F
integrated oscillator. F
332
REF
F
REF
F
is 27 MHz, generated by an external crystal and an
OUT
Integrated PLL
= (m + 1) / (n+ 1) x F
Divider
n
OUT
32579B
is calculated from:
REF
Compare
Phase
Figure 7-16. PLL Block Diagram
Divider
m
Charge
Pump
The integrated PLL can generate any frequency by writing
into the CRT-m and CRT-n bit fields (FBAR0+Memory Off-
set 2Ch). Additionally, 16 preprogrammed VGA frequencies
can be selected via the PLL Clock Select register
(F4BAR0+Memory Offset 2Ch[19:16]), if the crystal oscilla-
tor has a frequency of 27 MHz. This PLL can be powered
down via the Miscellaneous register (F4BAR0+Memory
Offset 28h[12]).
Loop
Filter
AMD Geode™ SC1200/SC1201 Processor Data Book
VCO
Video Processor Module
Divide
Out
F
OUT