DESCRIPTION OF PIN FUNCTIONS
BUFFER TYPE
PER
PIN
No./
QFP
BUFFER
TYPE
FUNCTION
(NOTE 1)
NAME
TOTAL
SYMBOL
NOTE
S
PROCESSOR/HOST LPC INTERFACE (10)
23:20 Multiplexed Command,
4
LAD[3:0]
PCI_IO
PCI_IO
Address, Data [3:0]
24
25
26
Frame
1
1
1
nLFRAME
nLDRQ
PCI_I
PCI_O
PCI_I
PCI_I
PCI_O
PCI_I
Encoded DMA Request
PCI Reset
nPCI_RESE
T
27
29
Power Down
PCI Clock
1
1
nLPCPD
PCI_CLK
PCI_I
PCI_I
PCI_ICLK
2
PCI_ICL
K
30
Serial IRQ
1
SER_IRQ
CLOCKS (2)
CLOCKI32
PCI_IO
PCI_IO
6
32.768kHz Trickle
Clock Input
1
1
IS
IS
IS
IS
3
19
14.318MHz Clock Input
CLOCKI
FAN CONTROL (4)
51
52
54
55
General Purpose I/O
/Fan Tachometer 2
General Purpose I/O
/Fan Tachometer 1
General Purpose I/O
/Fan Speed Control 2
General Purpose I/O
/Fan Speed Control 1
1
GP30/
IO8
(I/O8/OD8)/I
(I/O8/OD8)/I
FAN_TACH2
1
1
1
GP31/
IO8
FAN_TACH1
GP32/FAN2
IO12
IO12
(I/O12/OD12)/
(O12/OD12)
4
GP33/FAN1
(I/O12/OD12)/
4
(O12/OD12)
INFRARED INTERFACE (2)
61
62
Infrared Rx
1
IRRX2/GP34 IS/O8
IS/(IS/O8/OD8)
/General Purpose I/O
Infrared Tx
/General Purpose I/O
1
IRTX2/GP35 IO12
O12/(I/O12/
OD12)
5,6
POWER PINS (10)
53,
+3.3 Volt Supply
3
4
VCC
65,93 Voltage
7, 31, Ground
VSS
60,76
40
44
18
Analog Ground
1
1
1
AVSS
VREF
VTR
Reference Voltage
+3.3 Volt Standby
8
Supply Voltage
FDD INTERFACE (14)
16
11
10
12
8
Read Disk Data
Write Gate
Write Disk Data
Head Select
Step Direction
Step Pulse
1
1
1
1
1
1
1
1
1
1
nRDATA
nWGATE
nWDATA
nHDSEL
nDIR
IS
IS
O12
O12
O12
O12
O12
IS
(O12/OD12)
(O12/OD12)
(O12/OD12)
(O12/OD12)
(O12/OD12)
IS
9
nSTEP
4
Disk Change
Drive Select 0
Motor On 0
nDSKCHG
nDS0
nMTR0
nWRTPRT
5
O12
O12
IS
(O12/OD12)
(O12/OD12)
IS
3
15
Write Protected
SMSC LPC47B27x
- 9 -
Rev. 08-10-04
DATASHEET
SMSC [ SMSC CORPORATION ]
