Philips Semiconductors

User’s Manual - Preliminary -

 

 

 

 

 

 

UART (P89LPC903)

P89LPC901/902/903

 

.

SCON

Address: 98h Bit addressable

Reset Source(s): Any reset

Reset Value: 00000000B

7

6

5

4

3

2

1

0

SM0/FE

SM1

SM2

REN

TB8

RB8

TI

RI

 

 

 

 

 

 

 

 

BIT

SYMBOL

FUNCTION

 

SCON.7

SM0/FE

The use of this bit is determined by SMOD0 in the PCON register. If SMOD0 = 0, this bit

 

 

is read and written as SM0, which with SM1, defines the serial port mode. If SMOD0 = 1,

 

 

this bit is read and written as FE (Framing Error). FE is set by the receiver when an invalid

 

 

stop bit is detected. Once set, this bit cannot be cleared by valid frames but is cleared by

 

 

software. (Note: UART mode bits SM0 and SM1 should be programmed when SMOD0 is

 

 

’0’ - default mode on any reset.)

SCON. 6

SM1

With SM0, defines the serial port mode (see table below).

 

SM0, SM1

UART Mode

UART 0 Baud Rate

 

0 0

0: shift register

CCLK/16 (default mode on any reset)

 

0 1

1: 8-bit UART

Variable (see Table )

 

1 0

2: 9-bit UART

CCLK/32 or CCLK/16

 

1 1

3: 9-bit UART

Variable (see Table )

SCON.5

SM2

Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or 3, if

 

 

SM2 is set to 1, then Rl will not be activated if the received 9th data bit (RB8) is 0. In Mode

 

 

0, SM2 should be 0. In Mode 1, SM2 must be 0.

SCON.4

REN

Enables serial reception. Set by software to enable reception. Clear by software to disable

 

 

reception.

 

SCON.3

TB8

The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as

 

 

desired.

 

SCON.2

RB8

The 9th data bit that was received in Modes 2 and 3. In Mode 1 (SM2 must be 0), RB8 is

 

 

the stop bit that was received. In Mode 0, RB8 is undefined.

SCON.1

TI

Transmit interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the

 

 

the stop bit (see description of INTLO bit in SSTAT register) in the other modes. Must be

 

 

cleared by software.

SCON.0

RI

Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or

 

 

approximately halfway through the stop bit time in Mode 1. For Mode 2 or Mode 3, if

SMOD0, it is set near the middle of the 9th data bit (bit 8). If SMOD0 = 1, it is set near the middle of the stop bit (see SM2 - SCON.5 - for exceptions). Must be cleared by software.

Figure 8-3: Serial Port Control Register (SCON)

2003 Dec 8

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Philips P89LPC903, P89LPC901, P89LPC902 user manual Scon

P89LPC903, P89LPC902, P89LPC901 specifications

The Philips P89LPC901, P89LPC902, and P89LPC903 are a series of 8-bit microcontrollers designed for embedded system applications. These models, which belong to the LPC900 series, are notable for their affordability and versatility, making them an attractive choice for both hobbyists and professional developers.

One of the core features of the P89LPC901, P89LPC902, and P89LPC903 microcontrollers is their powerful 8-bit architecture. Operating at clock speeds up to 20 MHz, they deliver efficient performance suited for a range of tasks. Each model includes a comprehensive instruction set that supports various data manipulation and arithmetic functions, enabling extensive programming capabilities.

These microcontrollers come with built-in memory, with configurations that vary among the three models. The P89LPC901 typically features 4 KB of Flash memory and 256 bytes of RAM, while the P89LPC902 and P89LPC903 offer enhanced memory options. This Flash memory allows for reprogrammability, making it easier to update and modify applications as needed.

Another significant characteristic of the LPC900 series is their integrated peripherals. These models are equipped with a variety of I/O ports, allowing for easy interfacing with other devices and components. The P89LPC901 supports up to 32 I/O pins, while the P89LPC902 and P89LPC903 provide additional features such as analog-to-digital converters (ADCs), timers, and serial communication interfaces. This broad range of peripherals empowers developers to design complex applications without needing extra hardware.

Power consumption is also a key consideration for microcontroller applications. The P89LPC901, P89LPC902, and P89LPC903 are designed with low power consumption in mind, making them ideal for battery-operated devices and energy-efficient projects. They can operate in various power modes, allowing for greater flexibility in deployment.

In terms of technology, these microcontrollers utilize advanced CMOS technology, ensuring high reliability and durability. Their design offers a robust solution for numerous applications, including consumer electronics, industrial controls, and automation systems.

In summary, the Philips P89LPC901, P89LPC902, and P89LPC903 microcontrollers present an attractive combination of performance, integrated peripherals, low power consumption, and versatility. Their features cater to a wide array of applications, keeping them relevant in a rapidly evolving technology landscape. For hobbyists and professionals alike, these microcontrollers represent a reliable foundation for embedded system development.