CY28344 Cypress Semiconductor, CY28344 Datasheet - Page 2

• Manufacturer Part Number: CY28344
• Description: FTG
• Manufacturer: Cypress Semiconductor

Pin Definitions
Document #: 38-07113, Rev. *A
X1
X2
REF_2X/FS2
MULTSEL0
CPU0:2, CPU0:2#
3V66_1:3
3V66_0/VCH_CLK/F
S4
PCI_F0/FS0
PCI_F1/FS1
PCI0:6
48MHz/FS3
24_48MHz
SCLK
SDATA
RST#
IREF
VTT_PWRGD/PD#
VDD_REF,
VDD _PCI,
VDD_48MHz,
VDD_3V66,
VDD_CPU
VDD_48MHz
GND_PCI,
GND_48MHz,
GND_3V66,
GND_CPU,
GND_REF,
Pin Name
1, 7, 13, 18,
4, 8, 14, 19,
47, 44, 40,
12, 15, 16,
30, 33, 41,
29, 32, 36,
20, 21, 22
46, 43,39
9, 10, 11,
Pin No.
38
17
34
23
48
31
35
28
27
37
26
45
42
33
2
3
5
6
(open-
drain)
Type
Pin
I/O
I/O
I/O
I/O
I/O
I/O
I/O
O
O
O
O
O
G
P
P
I
I
I
I
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.
Crystal Connection: Connection for an external 14.318-MHz crystal. If using an
external reference, this pin must be left unconnected.
Reference Clock/Frequency Select 2: 3.3V 14.318-MHz clock output. This pin
also serves as a power-on strap option to determine device operating frequency as
described in the Frequency Selection Table.
Current Multiplier Selection 0: 3.3V input to select the current multiplier for CPU
clock outputs. The MULTSEL0 is as follows:
MULTSEL0
0 = Ioh is 4 × IREF
1 = Ioh is 6 × IREF
CPU Clock Outputs: Frequency is set by the FS0:4 inputs or through serial input
interface.
66MHz Clock Outputs: 3.3V 66-MHz clock.
66MHz Clock Output/Frequency Select 4: 3.3V 66-MHz or 48-MHz clock output.
The selection is determined by the control byte register. This pin also serves as a
power-on strap option to determine device operating frequency as described in the
Frequency Selection Table.
Free-running PCI Output 0/Frequency Select 0: 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.
Free-running PCI Output 1/Frequency Select 1: 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 Clock Output 0 to 6: 3.3V PCI clock outputs.
48MHz Output/Frequency Select 3: 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 the Frequency Selection Table.
24 or 48MHz Output: 3.3V fixed 24-MHz or 48-MHz non-spread spectrum output.
SMBus Clock Input: Clock pin for serial interface.
SMBus Data Input: Data pin for serial interface.
System Reset Output: Open-drain system reset output.
Current Reference for CPU output: A precision resistor is attached to this pin,
which is connected to the internal current reference.
Powergood from Voltage Regulator Module (VRM)/PD#: 3.3V LVTTL input.
VTT_PWRGD# is a level sensitive strobe used to determine when FS0:4 and
MULTSEL0 inputs are valid and OK to be sampled (Active HIGH).
3.3V Power Connection: Power supply for CPU outputs buffers, 3V66 output
buffers, PCI output buffers, reference output buffers and 48-MHz output buffers.
Connect to 3.3V.
3.3V Power Connection: 48MHz output buffers. Connect to 3.3V.
Ground Connection: Connect all ground pins to the common system ground
plane.
PRELIMINARY
Pin Description
CY28344
Page 2 of 22