CY28349B
Pin Definitions
Pin
Type
Pin Name
Pin No.
Pin Description
X1
3
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.
X2
4
O
Crystal Connection: Connection for an external 14.318-MHz crystal. If using an
external reference, this pin must be left unconnected.
REF0/MULTSEL0
48
I/O
Reference Clock 0/Current Multiplier Selection 0: 3.3V 14.318-MHz clock
output. This pin also serves as a power-on strap option to determine the current
multiplier for the CPU clock outputs. The MULTSEL1:0 definitions are as follows:
MULTSEL1:0
00 = Ioh is 4 x IREF
01 = Ioh is 5 x IREF
10 = Ioh is 6 x IREF
11 = Ioh is 7 x IREF
REF1/MULTSEL1
1
I/O
Reference Clock 1/Current Multiplier Selection 1: 3.3V 14.318-MHz clock
output. This pin also serves as a power-on strap option to determine the current
multiplier for the CPU clock outputs. The MULTSEL1:0 definitions are as follows:
MULTSEL1:0
00 = Ioh is 4 x IREF
01 = Ioh is 5 x IREF
10 = Ioh is 6 x IREF
11 = Ioh is 7 x IREF
CPU0:1, CPU0:1#
41, 38, 40, 37
44, 45
O
CPU Clock Outputs: Frequency is set by the FS0:4 inputs or through serial input
interface.
CPU_ITP, CPU_ITP#
I/O
CPU Clock Output for ITP: Frequency is set by the FS0:4 inputs or through serial
input interface.
3V66_0:2
31, 30, 28
6
O
66-MHz Clock Outputs: 3.3V fixed 66-MHz clock.
PCI_F0/FS2
I/O
Free-running PCI Output 0/Frequency Select 2: 3.3V free-running PCI output.
This pin also serves as a power-on strap option to determine device operating
frequency as described in the Frequency Selection Table.
PCI_F1/FS3
7
I/O
Free-running PCI Output 1/Frequency Select 3: 3.3V free-running PCI output.
This pin also serves as a power-on strap option to determine device operating
frequency as described in Table 4.
PCI_F2
8
I/O
I/O
Free-running PCI Output 2: 3.3V free-running PCI output.
PCI0/FS4
10
PCI Output 0/Frequency Select 4: 3.3V PCI output. This pin also serves as a
power-on strap option to determine device operating frequency as described in
Table 4.
PCI1:6
11,12,14,15,
16, 17
O
PCI Clock Output 1 to 6: 3.3V PCI clock outputs.
48MHz_0/FS0
22
I/O
48-MHz Output/Frequency Select 0: 3.3V fixed 48-MHz, non-spread spectrum
output. This pin also serves as a power-on strap option to determine device
operating frequency as described in Table 4.
This output will be used as the reference clock for USB host controller in Intel 845
(Brookdale) platforms. For Intel Brookdale – G platforms, this output will be used
as the VCH reference clock.
24_48MHz/FS1
23
I/O
24- or 48-MHz Output/Frequency Select 1: 3.3V fixed 24-MHz or 48-MHz
non-spread spectrum output. This pin also serves as a power-on strap option to
determine device operating frequency as described in Table 4.
This output will be used as the reference clock for SIO devices in Intel 845
(Brookdale) platforms. For Intel Brookdale – G platforms, this output will be used
as the reference clock for both USB host controller and SIO devices. We
recommend system designer to configure this output as 48 MHz and “HIGH Drive”
by setting Byte [5], Bit [0] and Byte [9], Bit [7], respectively.
3V66_3/48MHz_1
27
O
48-MHz or 66-MHz Output: 3.3V output.
Rev 1.0,November 20, 2006
Page 2 of 20
SPECTRALINEAR [ SPECTRALINEAR INC ]
