Philips Semiconductors

User’s Manual - Preliminary -

 

 

 

 

 

 

UART (P89LPC903)

P89LPC901/902/903

 

 

More About UART Modes 2 and 3

 

 

Reception is the same as in Mode 1.

The signal to load SBUF and RB8, and to set RI, will be generated if, and only if, the following conditions are met at the time the final shift pulse is generated. (a) RI = 0, and (b) Either SM2 = 0, or the received 9th data bit = 1. If either of these conditions is not met, the received frame is lost, and RI is not set. If both conditions are met, the received 9th data bit goes into RB8, and the first 8 data bits go into SBUF.

TX Clock

 

 

 

 

 

 

 

 

 

 

 

 

Write to SBUF

 

 

 

 

 

 

 

 

 

 

 

 

Shift

 

 

 

 

 

 

 

 

 

 

 

 

TxD

 

 

D0

D1

D2

D3

D4

D5

D6

D7

 

Transmit

 

Bit

TB8

Stop Bit

 

 

TI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INTLO = 0

INTLO = 1

 

 

 

 

 

 

 

 

 

 

 

 

RX Clock

 

 

 

 

 

 

 

 

 

 

 

 

RxD

÷ 16 Reset

Start Bit

D0

D1

D2

D3

D4

D5

D6

D7

RB8

Stop Bit

Shift

 

 

 

 

 

 

 

 

 

 

 

Receive

 

 

 

 

 

 

 

 

 

 

 

 

RI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SMOD0 = 0

SMOD0 = 1

 

 

 

 

 

 

 

 

 

 

 

 

Figure 8-7: Serial Port Mode 2 or 3 (Only Single Transmit Buffering Case Is Shown)

Framing Error and RI in Modes 2 and 3 with SM2 = 1

If SM2 = 1 in modes 2 and 3, RI and FE behave as in the following table.

Mode

PCON.6

RB8

RI

FE

(SMOD0)

 

 

 

 

 

 

 

 

 

 

 

0

No RI when RB8 = 0

Occurs during STOP bit

2

0

 

 

 

1

Similar to Figure 8-7, with SMOD0 = 0, RI

Occurs during STOP bit

 

 

occurs during RB8, one bit before FE

 

 

 

 

 

 

 

 

 

 

 

0

No RI when RB8 = 0

Will NOT occur

3

1

 

 

 

1

Similar to Figure 8-7, with SMOD0 = 1, RI

Occurs during STOP bit

 

 

occurs during STOP bit

 

 

 

 

 

 

 

 

 

Table 8-3: FE and RI when SM2 = 1 in Modes 2 and 3.

Break Detect

A break is detected when 11 consecutive bits are sensed low and is reported in the status register (SSTAT). For Mode 1, this consists of the start bit, 8 data bits, and two stop bit times. For Modes 2 & 3, this consists of the start bit, 9 data bits, and one stop bit. The break detect bit is cleared in software or by a reset. The break detect can be used to reset the device. This occurs if the UART is enabled and the the EBRR bit (AUXR1.6) is set and a break occurs.

2003 Dec 8

67

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Philips P89LPC903, P89LPC902 P89LPC901/902/903 More About Uart Modes 2, Framing Error and RI in Modes 2 and 3 with SM2 =

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.