
CY28548
........................Document #: 001-08400 Rev ** Page 2 of 30
Pin Configuration
64-Pin TSSOP
CY285
48
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
SDATA
SCLK
REF0/FSC/TEST_SEL
VDD_REF
XIN
XOUT
VSS_REF
CKPWRGD/PWRDWN#
FSB/TEST_MODE
CPUT0
CPUC0
VSS_CPU
CPUT1
CPUC1
VDD_CPU_IO
NC
SRCT8/CPU2_ITPT
SRCC8/CPU2_ITPC
VDD_SRC_IO
SRCT7/CR#_F
SRCC7/CR#_E
VSS_SRC
SRCT6
SRCC6
VDD_SRC
PCI_STOP#
CPU_STOP#
VDD_CPU
40
39
38
37
36
35
34
33
VDD_SRC_IO
SRCC10
SRCT10
SRCT11/CR#_H
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
1
2
3
4
5
6
7
VDD_PCI
PCI0/CR#_A
PCI1/CR#_B
PCI2/TME
PCI3
PCI4/GCLK_SEL
PCIF0/ITP_EN
VDD_48
VSS_PCI
VSS_48
VDD_IO
SRCT0/DOT96T
SRCC0/DOT96C
VSS_IO
VDD_PLL3
SRCT1/LCDT_100/27M_NSS
SRCC1/LCDC_100/27M_SS
VSS_PLL3
VDD_PLL3_IO
SRCT2/SATAT
SRCC2/SATAC
VSS_SRC
SRCT3/CR#_C
SRCC3/CR#_D
VDD_SRC
SRCT4
SRCC4
USB_48/FSA
25
26
27
28
29
30
31
32
VSS_SRC_IO
SRCT9
SRCC9
SRCC11/CR#_G
64-Pin QFN
QFN Pin Definitions
Pin No.
Name
Type
Description
1
VSS_REF
GND
Ground for outputs.
2
Xout
O, SE 14.318 MHz Crystal output.
3Xin
I
14.318 MHz Crystal input.
4
VDD_REF
PWR
3.3V Power supply for outputs and maintains SMBUS registers during power
down.
5
REF0 / FSC / TEST_SEL
I/O
Fixed 14.318 clock output/3.3V-tolerant input for CPU frequency selection/
Selects test mode if pulled to VIHFS_C when CK_PWRGD is asserted HIGH.
Refer to DC Electrical Specifications table for VILFS_C, VIMFS_C, VIHFS_C specifica-
tions.
6SDATA
I/O
SMBus compatible SDATA.
7SCLK
I
SMBus compatible SCLOCK.