LPC2157_2158_2

© NXP B.V. 2009. All rights reserved.

Product data sheet

Rev. 02 — 9 February 2009

9 of 45

NXP Semiconductors

LPC2157/2158

Single-chip 16-bit/32-bit microcontrollers

[1]

5 V tolerant pad providing digital I/O functions with TTL levels and hysteresis and 10 ns slew rate control.

[2]

5 V tolerant pad providing digital I/O functions with TTL levels and hysteresis and 10 ns slew rate control. If configured for an input

function, this pad utilizes built-in glitch filter that blocks pulses shorter than 3 ns.

[3]

functionality.

[4]

5 V tolerant pad providing digital I/O (with TTL levels and hysteresis and 10 ns slew rate control) and analog input function. If configured

for an input function, this pad utilizes built-in glitch filter that blocks pulses shorter than 3 ns. When configured as an ADC input, digital

section of the pad is disabled.

[5]

5 V tolerant pad providing digital I/O (with TTL levels and hysteresis and 10 ns slew rate control) and analog output function. When

configured as the DAC output, digital section of the pad is disabled.

[6]

5 V tolerant pad with built-in pull-up resistor providing digital I/O functions with TTL levels and hysteresis and 10 ns slew rate control.

The pull-up resistor’s value typically ranges from 60 k

Ω to 300 kΩ.

[7]

Pad is designed in accordance with the Universal Serial Bus (USB) specification, revision 2.0 (Full-speed and Low-speed mode only).

[8]

5 V tolerant pad providing digital input (with TTL levels and hysteresis) function only.

[9]

Pad provides special analog functionality.

RESET

83[8]

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

88[9]

O

Input from the oscillator amplifier.

XTAL2

87[9]

I

Output to the oscillator circuit and internal clock generator circuits.

RTCX1

93[9]

I

Input to the RTC oscillator circuit.

RTCX2

94[9]

O

Output from the RTC oscillator circuit.

6, 13, 32,

39, 40,

85, 95

I

Ground: 0 V reference.

11, 27, 33 I

3.3 V power supply: This is the power supply voltage for the core and I/O

ports.

96

I

Analog 3.3 V power supply: This should be nominally the same voltage as

used to power the on-chip ADC(s) and DAC.

38

I

1.8 V to 5.5 V power supply: Power supply voltage for the PCF8576D.

41

I

LCD power supply: LCD voltage.

VREF

89

I

ADC reference voltage: This should be nominally less than or equal to the

pin is used as a reference for ADC(s) and DAC.

VBAT

31

I

RTC power supply voltage: 3.3 V on this pin supplies the power to the RTC.

SDA_LCD

34

I/O

SCL_LCD

35

I

SYNC

36

I/O

SYNC — cascade synchronization input/output

CLK

37

I/O

CLK — external clock input/output

BP0 to BP3

42 to 45

O

BP0 to BP3: LCD backplane outputs.

S0 to S31

46 to 77

O

S0 to S31: LCD segment outputs.

Table 2.

Symbol

Pin

Type

Description