
ICS8430S07AKI REVISION A SEPTEMBER 3, 2009
3
2009 Integrated Device Technology, Inc.
ICS8430S07I Data Sheet
CLOCK GENERATOR FOR CAVIUM PROCESSORS
Table 1. Pin Descriptions
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
Number
Name
Type
Description
1, 15
VDD
Power
Core supply pins.
2
nPLL_SEL
Input
Pulldown
PLL bypass. When LOW, selects PLL (PLL Enable). When HIGH, bypasses
the PLL. LVCMOS/LVTTL interface levels.
3, 4
XTAL_IN,
XTAL_OUT
Input
Parallel resonant crystal interface. XTAL_OUT is the output, XTAL_IN is the
input.
5
nXTAL_SEL
Input
Pulldown
Selects XTAL inputs when LOW. Selects differential clock (CLK, nCLK) input
when HIGH. LVCMOS/LVTTL interface levels.
6
CLK
Input
Pulldown
Non-inverting differential clock input.
7
nCLK
Input
Pullup/
Pulldown
Inverting differential clock input. Internal resistor bias to VDD/2.
8, 20, 21, 27
GND
Power
Power supply ground.
9, 10
PCI_SEL1,
PCI_SEL0
Input
Pulldown
Selects the PCI/PCI-X reference clock output frequency. See Table 3C.
LVCMOS/LVTTL interface levels.
11, 12
DDR_SEL1,
DDR_SEL0
Input
Pulldown
Selects the DDR reference clock output frequency. See Table 3B.
LVCMOS/LVTTL interface levels.
13, 14
nQA, QA
Output
Differential output pair. LVPECL interface levels.
16
VDDA
Power
Analog supply pin.
17
VDDO_B
Power
Bank B output supply pin. 3.3 V or 2.5V supply.
18, 23, 26,
29, 30,
31
QB, QC, QD,
QREF2, QREF1,
QREF0
Output
Single-ended outputs. LVCMOS/LVTTL interface levels.
19
MR/nOE_REF
Input
Pulldown
Active HIGH Master Reset. Active LOW output enable. When logic HIGH, the
internal dividers are reset and the QREF[2:0] outputs are in high impedance
(HI-Z). When logic LOW, the internal dividers and the outputs are enabled.
LVCMOS/ LVTTL interface levels.
22
CORE_SEL
Input
Pulldown
Selects the processor core clock output frequency. The output frequency is
50MHz when LOW, and 33.333MHz when HIGH. See Table 3A.
LVCMOS/LVTTL interface levels.
24
VDDO_C
Power
Bank C output supply pin. 3.3 V or 2.5V supply.
25
VDDO_D
Power
Bank D output supply pin. 3.3 V or 2.5V supply.
28, 32
VDDO_REF
Power
REF bank output supply pins. 3.3 V or 2.5V supply.