NXP Semiconductors LPC24XX UM10237 - Manual (Page 154)

UM10237_4 © NXP B.V. 2009. All rights reserved.
User manual Rev. 04 — 26 August 2009 154 of 792
NXP Semiconductors
UM10237
Chapter 8: LPC24XX Pin configuration
[1] 5 V tolerant pad providing digital I/O functions with TTL levels and hysteresis.
TCK 10 [1] E2 [1] I TCK — Test Clock for JTAG interface. This clock must be slower than 1 ⁄
6
of the CPU clock (CCLK) for the JTAG interface to operate.
RTCK 206 [1] C3 [1] I/O RTCK — JTAG interface control signal.
Note: LOW on this pin while RESET is LOW enables ETM pins (P2[9:0])
to operate as Trace port after reset.
RSTOUT 29 K3 O RSTOUT — This is a 3.3 V pin. LOW on this pin indicates UM10237
being in Reset state.
RESET 35 [7] M2 [7] I external reset input: A LOW on this pin resets the device, causing I/O
ports and peripherals to take on their default states, and processor
execution to begin at address 0. TTL with hysteresis, 5 V tolerant.
XTAL1 44 [8] M4 [8] I Input to the oscillator circuit and internal clock generator circuits.
XTAL2 46 [8] N4 [8] O Output from the oscillator amplifier.
RTCX1 34 [8] K2 [8] I Input to the RTC oscillator circuit.
RTCX2 36 [8] L2 [8] O Output from the RTC oscillator circuit.
V
SSIO
33, 63,
77, 93,
114,
133,
148,
169,
189,
200
[8]
L3, T5,
R9,
P12,
N16,
H14,
E15,
A12,
B6, A2
[8]
I ground: 0 V reference for the digital I/O pins.
V
SSCORE
32, 84,
172
[8]
K4, P10,
D12
[8]
I ground: 0 V reference for the core.
V
SSA
22 [8] J2 [8] I analog ground: 0 V reference. This should nominally be the same
voltage as V
SSIO
/V
SSCORE
, but should be isolated to minimize noise and
error.
V
DD(3V3)
15, 60,
71, 89,
112,
125,
146,
165,
181,
198
[8]
G3,
P6, P8,
U13,
P17,
K16,
C17,
B13,
C9,
D7
[8]
I 3.3 V supply voltage: This is the power supply voltage for the I/O ports.
n.c. 30, 117,
141
[8]
J4, L14,
G14
[8]
I not connected pins: These pins must be left unconnected (floating).
V
DD(DCDC)(3V3)
26, 86,
174
[8]
H4, P11,
D11
[8]
I 3.3 V DC-to-DC converter supply voltage: This is the power supply for
the on-chip DC-to-DC converter.
V
DDA
20 [8] G4 [8] I analog 3.3 V pad supply voltage: This should be nominally the same
voltage as V
DD(3V3)
but should be isolated to minimize noise and error.
This voltage is used to power the ADC and DAC.
VREF 24 [8] K1 [8] I ADC reference: This should be nominally the same voltage as V
DD(3V3)
but should be isolated to minimize noise and error. The level on this pin is
used as a reference for ADC and DAC.
VBAT 38 [8] M3 [8] I RTC power supply: 3.3 V on this pin supplies the power to the RTC.
Table 122. LPC2420/60/68 pin description …continued
Symbol Pin Ball Type Description