6.12 General Purpose I/O
The LPC47S45x provides a set of flexible Input/Output control functions to the system designer through the 55
dedicated independently programmable General Purpose I/O pins (GPIO). The GPIO pins can perform basic I/O and
many of them can be individually enabled to generate an SMI and a PME.
6.12.1 GPIO PINS
The following pins include GPIO functionality. These pins are defined in the table below.
Table 56 − GPIO Pin Functionality
REGISTER
DEFAULT
ON VTR
POR
REGISTER
DEFAULT
ON VCC
POR
SMI/PME
FUNCTIONALITY
PIN
NAME
POWER WELL
6
7
GP40 /DRVDEN0
GP41 /DRVDEN1
GP42 /IO_PME#
VCC
Input
Input
Input
-
-
-
-
VCC (Note 1)
VTR
PME/SMI
IO_PME#
20
GPIO
Function
31
GP43 /DDRC
VCC (Note 1)
Input
PME/SMI
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
GP80
VCC
Output,low
Output, low
Output, low
Output, low
Output, high
Output, high
Output, high
Output, high
Input
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
GP81
VCC
-
GP82
VCC
-
GP83
VCC
-
GP84
VCC
-
GP85
VCC
-
GP86
VCC
-
GP87
VCC
-
GP62 /IRQINC
GP20 /P17 /DS1#
GP21 /P16
GP22 /P12 / MTR1#
GP23 /IRQIND
GP24 /P17
GP25 /P12
GP26 SYSOPT
GP60 /LED1
GP61 /LED2
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VTR (Note 1)
VTR (Note 1)
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME
Input
Input
Input
Input
Input
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
/IO_SMI#
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
PME/SMI
Input
Input
Input
Input
53
GP27 /IO_SMI#
VCC (Note 1)
Input
-
54
55
57
58
64
65
66
67
95
97
98
99
GP30 /nXCS2
GP31 /nXCS3
GP32 /FAN_TACH
GP33 /FAN
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VCC (Note 1)
VTR (Note 1)
VCC (Note 1)
VCC (Note 1)
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Output, low
Input
Input
-
-
-
Output, low
GP34 /IRQINA
GP35 /IRQINB
GP36 /nKBDRST
GP37 /A20M
-
-
-
-
GP50 /RI2#
-
GP51 /DCD2#
GP52 /RXD2 /IRRX
GP53 /TXD2 /IRTX
-
-
Output, low
100 GP54 /DSR2#
-
-
101 GP55 /RTS2# /SADR0
SMSC LPC47S45x
Page 115 of 259
Rev. 06-01-06
DATASHEET
SMSC [ SMSC CORPORATION ]
