© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
User manual
Rev. 01 — 12 January 2006
18
Philips Semiconductors
UM10161
Volume 1
Chapter 3: System control block
3.5 External interrupt inputs
The LPC2101/02/03 includes up to three External Interrupt Inputs as selectable pin
functions. When the pins are combined, external events can be processed as three
independent interrupt signals. The External Interrupt Inputs can optionally be used to
wake up the processor from Power-down mode.
Additionally, all 10 capture inputs can also be used as external interrupts without the
option to wake up the device from Power-down mode.
15 MHz - 20 MHz
10 pF
< 220
Ω
18 pF, 18 pF
20 pF
< 140
Ω
38 pF, 38 pF
30 pF
< 80
Ω
58 pF, 58 pF
20 MHz - 25 MHz
10 pF
< 160
Ω
18 pF, 18 pF
20 pF
< 90
Ω
38 pF, 38 pF
30 pF
< 50
Ω
58 pF, 58 pF
25 MHz - 30 MHz
10 pF
< 130
Ω
18 pF, 18 pF
20 pF
< 50
Ω
38 pF, 38 pF
30 pF
NA
NA
Fig 7.
F
OSC
selection algorithm
Table 7:
Recommended values for C
X1/X2
in oscillation mode (crystal and external
components parameters)
Fundamental
oscillation frequency
F
OSC
Crystal load
capacitance C
L
Maximum crystal
series resistance R
S
External load
capacitors C
X1
,
CX2
true
MIN f
OSC
= 10 MHz
MAX f
OSC
= 25 MHz
true
MIN f
OSC
= 1 MHz
MAX f
OSC
= 50 MHz
MIN f
OSC
= 1 MHz
MAX f
OSC
= 30 MHz
mode a and/or b
mode a
mode b
on-chip PLL used
in application?
ISP used for initial
code download?
external crystal
oscillator used?
true
false
false
false
f
OSC
selection