CY28419
Pin Description
Pin No.
1,2
Pin Name
Pin Type
Pin Description
REF(0:1)
XIN
O, SE Reference Clock. 3.3V 14.318-Mz clock output.
4
I
Crystal Connection or External Reference Frequency Input. This pin has dual
functions. It can be used as an external 14.318-MHz crystal connection or as an
external reference frequency input.
5
XOUT
O, SE Crystal Connection. Connection for an external 14.318-MHz crystal output.
41,44,47,50 CPUT(0:3)
O, DIF CPU Clock Output. Differential CPU clock outputs. See Table 1 for frequency config-
uration.
40,43,46,49 CPUC(0:3)
O, DIF CPU Clock Output. Differential CPU clock outputs. See Table 1 for frequency config-
uration.
38, 37
SRCT, SRCC
O, DIF Differential serial reference clock.
22,23,26,27 3V66(3:0)
O, SE 66 MHz Clock Output. 3.3V 66-MHz clock from internal VCO.
O, SE 48/66 MHz Clock Output. 3.3V selectable through SMBus to be 66 or 48 MHz.
O, SE Free Running PCI Output. 33-MHz clocks divided down from 3V66.
O, SE PCI Clock Output. 33-MHz clocks divided down from 3V66.
29
3V66_4VCH
PCIF(0:2)
7,8,9
12,13,14,15, PCI(0:6)
18,19,20
31,
32
USB_48
DOT_48
FS_A, FS_B
IREF
O, SE Fixed 48 MHz clock output.
O, SE Fixed 48 MHz clock output.
51,56
52
I
I
3.3V LVTTL input for CPU frequency selection.
Current Reference. A precision resistor is attached to this pin which is connected to
the internal current reference.
21
35
PD#
I, PU
I
3.3V LVTTL input for power-down# active LOW.
VTT_PWRGD#
3.3V LVTTL input is a level-sensitive strobe used to latch the FS0 input (active
LOW).
30
SDATA
I/O
SMBus-compatible SDATA.
SMBus-compatible SCLOCK.
Ground for current reference.
3.3V power supply for PLL.
Ground for PLL.
28
SCLK
I
53
VSS_IREF
VDD_A
GND
PWR
GND
PWR
GND
PWR
GND
PWR
GND
PWR
GND
PWR
GND
PWR
GND
55
54
VSS_A
42,48
45
VDD_CPU
VSS_CPU
VDD_SRC
VSS_SRC
VDD_48
3.3V power supply for outputs.
Ground for outputs.
36
3.3V power supply for outputs.
Ground for outputs.
39
34
3.3V power supply for outputs.
Ground for outputs.
33
VSS_48
10,16
11,17
24
VDD_PCI
VSS_PCI
VDD_3V66
VSS_3V66
VDD_REF
VSS_REF
3.3V power supply for outputs.
Ground for outputs.
3.3V power supply for outputs.
Ground for outputs.
25
3
3.3V power supply for outputs.
Ground for outputs.
6
Rev 1.0,November 22, 2006
Page 2 of 15
SPECTRALINEAR [ SPECTRALINEAR INC ]
