Philips Semiconductors

 

 

 

 

 

 

 

 

User’s Manual - Preliminary -

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESET

 

 

 

 

 

 

 

 

P89LPC901/902/903

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RSTSRC

 

7

6

5

4

3

2

1

0

 

 

 

Address: DFH

 

 

 

 

Not bit addressable

 

-

-

 

BOF

POF

R_BK

R_WD

R_SF

R_EX

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset Sources: Power-on only

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset Value: xx110000B (This is the power-on reset value. Other reset sources will set corresponding bits.)

 

 

 

 

BIT

SYMBOL

FUNCTION

 

 

 

 

 

 

 

 

 

 

 

RSTSRC.7-6

-

Reserved for future use. Should not be set to 1 by user programs.

 

 

 

 

RSTSRC.5

BOF

Brownout Detect Flag. When Brownout Detect is activated, this bit is set. It will remain set

 

 

 

 

until cleared by software by writing a ’0’ to the bit. (Note: On a Power-on reset, both POF

 

 

 

 

and this bit will be set while the other flag bits are cleared.)

 

 

 

 

 

RSTSRC.4

POF

Power-on Detect Flag. When Power-on Detect is activated, the POF flag is set to indicate

 

 

 

 

an initial power-up condition. The POF flag will remain set until cleared by software by

 

 

 

 

writing a ’0’ to the bit.. (Note: On a Power-on reset, both BOF and this bit will be set while

 

 

 

 

the other flag bits are cleared.)

 

 

 

 

 

 

 

 

RSTSRC.3

R_BK

Break detect reset. If a break detect occurs and EBRR (AUXR1.6) is set to ’1’, a system

 

 

 

 

reset will occur. This bit is set to indicate that the system reset is caused by a break detect.

 

 

 

 

Cleared by software

by writing a ’0’ to the bit or on a Power-on reset.

 

 

 

 

RSTSRC.2

R_WD

Watchdog Timer reset flag. Cleared by software by writing a ’0’ to the bit or a Power-on

 

 

 

 

reset.(NOTE: UCFG1.7 must be = 1).

 

 

 

 

 

 

 

RSTSRC.1

R_SF

Software reset Flag. Cleared by software by writing a ’0’ to the bit or a Power-on reset.

 

 

RSTSRC.0

R_EX

External reset Flag. When this bit is ’1’, it indicates external pin reset. Cleared by software

 

 

 

 

by writing a ’0’ to the bit or a Power-on reset. If RST is still asserted after the Power-on

 

 

 

 

reset is over, R_EX will be set.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 9-2: Reset Sources Register

2003 Dec 8

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Philips P89LPC902, P89LPC901, P89LPC903 user manual Rstsrc
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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.
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