VT8601 Via, VT8601 Datasheet - Page 27

• Manufacturer Part Number: VT8601
• Description: Slot-1 / Socket-370 PCI North Bridge
• Manufacturer: Via

Signal Name
VCCA
GNDA
VCCV1
GNDV1
VLF1
VCCV2
GNDV2
VLF2
PLLTST
Signal Name
VCCS
GNDS
COMP
IRSET
GNDRGB
Commonly Used Prefix / Suffix Letters in Signal Names:
I = Internal Logic
M = Memory (SDRAM) Interface
H = Host CPU Interface
P = PCI Bus Interface
G = AGP Bus (internal in ProMedia)
GM = Graphics Memory Interface
U (or USB) = USB (Universal Serial Bus)
H (or HWM) = Hardware Monitoring
SUS = Suspend Power
Revision 1.3 September 8, 1999
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H21, H22
L21, L22
Pin #
Pin #
AA1
AA2
K24
W2
Y1
Y3
Y2
A1
C1
B1
E4
E3
RAMDAC Output Power / Ground and Analog Control
I/O
I/O
A
A
A
A
P
P
P
P
P
P
P
P
P
Clock Power / Ground and Filtering
Signal Description
Power for North Bridge Clock Circuitry (2.5V ±5%). Connect to VCCI through a
ferrite bead and decouple to GNDA with 0.001Uf and 0.1Uf ceramic and 10Uf tantalum
capacitors (see “Apollo ProMedia Design Guide”).
Ground for North Bridge Clock Circuitry. Connect to main ground plane GND
through a ferrite bead. (see “Apollo ProMedia Design Guide”).
Power for Video Clock Synthesizer 1 Analog Circuitry (2.5V ±5%). Connect to
VCCI through a ferrite bead and decouple to GNDV1 with 0.001Uf and 0.1Uf ceramic
and 10Uf tantalum capacitors (see “Apollo ProMedia Design Guide”).
Ground for Video Clock Synthesizer 1. Connect to main ground plane through a
ferrite bead.
Low Pass Filter Capacitor for Video Clock Synthesizer 1. Connect to GNDV1
through a 560Pf capacitor.
Power for Video Clock Synthesizer 2 Analog Circuitry (2.5V ±5%). Connect to
VCCI through a ferrite bead and decouple to GNDV2 with 0.001Uf and 0.1Uf ceramic
and 10Uf tantalum capacitors (see “Apollo ProMedia Design Guide”).
Ground for Video Clock Synthesizer 2. Connect to main ground plane through a
ferrite bead.
Low Pass Filter Capacitor for Video Clock Synthesizer 2. Connect to GNDV2
through a 560Pf capacitor.
PLL Test. Pull down with 4.7K resistor for normal operation.
Signal Description
Power for RAMDAC Current Source Circuitry (2.5V ±5%). Connect to VCCI
through a ferrite bead and decouple to GNDS with 0.001uF and 0.1uF ceramic and 10uF
tantalum capacitors (see “Apollo ProMedia Design Guide”).
Ground for RAMDAC Current Source Circuitry. Connect to main ground plane
through a ferrite bead.
Compensation Capacitor. RAMDAC analog control. Connect to VCCS using a 0.1
uF capacitor.
RAMDAC Current Set Point Resistor. RAMDAC analog control. Connect to GNDS
through a 360 1% resistor.
RGB Video Output Return. Connection point for the RGB load resistors. Also used
as a shield for the RGB video output traces to the VGA display connector. Connects to
RGB return pins 6, 7, and 8 of the VGA connector. Connect to main ground plane
through a ferrite bead. Refer to the “Apollo ProMedia Design Guide” for more specific
connection and PCB layout details.
RGB = Analog Video Out Return
A = North Bridge Clock Synthesizer
V1 = Video Clock Synthesizer PLL1
V2 = Video Clock Synthesizer PLL2
D = Video Clocks Digital Data Path
R = RAMDAC Digital Data Path
S = RAMDAC Current Source
TV = TV Out
V = TV In / Video Capture
-21-
VT8601 Apollo ProMedia
Pinouts