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UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
75 of 571
NXP Semiconductors
UM10316
Chapter 6: LPC29xx System Control Unit (SCU)
shows the bit assignment of the SFSPn_m registers (n runs from 0 to 4, m
runs from 0 to 31. For port 5, m runs from 0 to 15).
Remark:
Note that on Reset the ADC pins P0[23] to P0[8] are set to digital inputs without
internal pull-up/down on reset. This guarantees that these pins are 5 V tolerant after reset,
even though the analog inputs to ADC1 and ADC2 are not. The default pad type is analog
input for all other port pins (except P5[19:16]).
SFSPn_22
58h
R/W
0000 0000h
Function-select port n, pin
22 register
see
SFSPn_23
5Ch
R/W
0000 0000h
Function-select port n, pin
23 register
see
SFSPn_24
60h
R/W
0000 0000h
Function-select port n, pin
24 register
see
SFSPn_25
64h
R/W
0000 0000h
Function-select port n, pin
25 register
see
SFSPn_26
68h
R/W
0000 0000h
Function-select port n, pin
26 register
see
SFSPn_27
6Ch
R/W
0000 0000h
Function-select port n, pin
27 register
see
SFSPn_28
70h
R/W
0000 0000h
Function-select port n, pin
28 register
see
SFSPn_29
74h
R/W
0000 0000h
Function-select port n, pin
29 register
see
SFSPn_30
78h
R/W
0000 0000h
Function-select port n, pin
30 register
see
SFSPn_31
7Ch
R/W
0000 0000h
Function-select port n, pin
31 register
see
Table 58.
SFSPn_m register bit description (base address: 0xE000 1000 (port 0), 0xE000
1100 (port 1), 0xE000 1200 (port 2), 0xE000 1300 (port3), 0xE000 1400 (port4),
0xE000 1500 (port 5))
* = reset value
Bit
Symbol
Access
Value
Description
31 to 5
reserved
R
-
Reserved. Read as logic 0
4 to 2
PAD_TYPE
R/W
Input pad type
000*
Analog input
001
Digital input without internal pull up/down
010
Not allowed
011
Digital input with internal pull up
100
Not allowed
101
Digital input with internal pull down
110
Not allowed
111
Digital input with bus keeper
Table 57.
SCU port function select register overview (base address: 0xE000 1000 (port 0),
0xE000 1100 (port 1), 0xE000 1200 (port 2), 0xE000 1300 (port3), 0xE000 1400
(port4), 0xE000 1500 (port 5))
…continued
Ports not pinned out are reserved; do not modify, read as logic 0.
Name
Address
offset
Access
Reset value
Description
Reference