LPC2158 datasheet(27/45 Pages) PHILIPS

27 / 45 page

LPC2157_2158_2

Product data sheet

Rev. 02 — 9 February 2009

27 of 45

NXP Semiconductors

LPC2157/2158

Single-chip 16-bit/32-bit microcontrollers

The JTAG clock (TCK) must be slower than 1

⁄

6 of the CPU clock (CCLK) for the JTAG

interface to operate.

6.20.2 RealMonitor

RealMonitor is a conﬁgurable software module, developed by ARM Inc., which enables

real-time debug. It is a lightweight debug monitor that runs in the background while users

debug their foreground application. It communicates with the host using the DCC, which is

present in the EmbeddedICE logic. The LPC2157/2158 contain a speciﬁc conﬁguration of

RealMonitor software programmed into the on-chip ﬂash memory.

6.21 LCD driver

6.21.1 General description

The LCD segment driver in the LPC2157/2158 can interface to most LCDs using low

multiplex rates. It generates the drive signals for static or multiplexed LCDs containing up

to four backplanes and up to 32 segments. The LCD controller communicates to a host

using the I2C-bus. The I2C-bus clock and data signals for both the microcontroller and the

LCD driver are available on the LPC2157/2158 providing system ﬂexibility.

Communication overhead to manage the display is minimized by an on-chip display RAM

with auto-increment addressing, hardware subaddressing, and display memory switching

(static and duplex drive modes). Please refer to PCF8576D data sheet for electrical data.

6.21.2 Functional description

The LCD controller is a versatile peripheral device designed to interface microcontrollers

to a wide variety of LCDs. It can directly drive any static or multiplexed LCD containing up

to four backplanes and up to 32 segments. The display conﬁgurations possible with the

LCD controller depend on the number of active backplane outputs required. A selection of

display conﬁgurations is shown in Table 4. All of these conﬁgurations can be implemented

in a typical system.

The microcontroller communicates to the LCD controller using the I2C-bus.The

appropriate biasing voltages for the multiplexed LCD waveforms are generated internally.

The only other connections required to complete the system are to the power supplies

(VDD(LCD), VSS and VLCD) and the LCD panel chosen for the application.

6.21.3 LCD bias voltages

LCD biasing voltages are obtained from an internal voltage divider consisting of three

series resistors connected between VLCD and VSS. The LCD voltage can be temperature

compensated externally via the supply to pin VLCD. A voltage selector drives the

multiplexing of the LCD based on programmable conﬁgurations.

Table 4.

Selection of display conﬁgurations

Number of

7-segments numeric

14-segments alphanumeric

Dot matrix

Backplanes

Segments

Digits

Indicator

symbols

Characters

Indicator

symbols

128

9612126

264

884864

132

442432

LPC2158 数据表(PDF) 27 Page - NXP Semiconductors

LPC2158 数据表(HTML) 27 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

数据表下载