Philips Semiconductors

 

 

 

 

 

 

 

 

User’s Manual - Preliminary -

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TIMERS 0 AND 1

 

 

 

 

 

P89LPC901/902/903

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TAMOD - P89LPC901

7

6

5

4

3

2

1

0

 

 

 

Address: 8Fh

 

 

-

-

-

-

-

-

 

-

T0M2

 

 

 

Not bit addressable

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset Source(s): Any reset

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset Value:

xxx0xxx0B

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT

SYMBOL

FUNCTION

 

 

 

 

 

 

 

 

 

 

 

TAMOD.7-1

-

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

 

 

 

 

TAMOD.0

T0M2

Mode Select bit 2 for Timer 0. Used with T0M1 and T0M0 in the TMOD register to

 

 

 

 

determine Timer 0 mode (P89LPC901).

 

 

 

 

 

 

 

 

 

TnM2-TnM0

Timer Mode

 

 

 

 

 

 

 

 

 

 

 

 

0 0 0

8048 Timer “TLn” serves as 5-bit prescaler. (Mode 0)

 

 

 

 

 

 

 

 

0 0 1

16-bit Timer/Counter “THn” and “TLn” are cascaded; there is no prescaler. (Mode 1)

 

 

 

0 1 0

8-bit auto-reload Timer/Counter. THn holds a value which is loaded into TLn when it

 

 

 

 

overflows. (Mode 2)

 

 

 

 

 

 

 

 

 

 

 

0 1 1

Timer 0 is a dual 8-bit Timer/Counter in this mode. TL0 is an 8-bit Timer/Counter controlled

 

 

 

 

by the standard Timer 0 control bits. TH0 is an 8-bit timer only, controlled by the Timer 1

 

 

 

 

control bits (see text). Timer 1 in this mode is stopped. (Mode 3)

 

 

 

 

 

1 0 0

Reserved. User must not configure to this mode.

 

 

 

 

 

 

 

 

1 0 1

Reserved. User must not configure to this mode.

 

 

 

 

 

 

 

 

1 1 0

PWM mode (see section "Mode 6 - P89LPC901").

 

 

 

 

 

 

 

 

1 1 1

Reserved. User must not configure to this mode.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 5-2: Timer/Counter Auxiliary Mode Control register (TAMOD)

Mode 0

Putting either Timer into Mode 0 makes it look like an 8048 Timer, which is an 8-bit Counter with a divide-by-32 prescaler. Figure 5-4 shows Mode 0 operation.

In this mode, the Timer register is configured as a 13-bit register. As the count rolls over from all 1s to all 0s, it sets the Timer interrupt flag TFn. The count input is enabled to the Timer when TRn = 1. TRn is a control bit in the Special Function Register TCON (Figure 5-3).

The 13-bit register consists of all 8 bits of THn and the lower 5 bits of TLn. The upper 3 bits of TLn are indeterminate and should be ignored. Setting the run flag (TRn) does not clear the registers.

Mode 0 operation is the same for Timer 0 and Timer 1. See Figure 5-4.

Mode 1 is the same as Mode 0, except that all 16 bits of the timer register (THn and TLn) are used. See Figure 5-5.

Mode 2

Mode 2 configures the Timer register as an 8-bit Counter (TLn) with automatic reload, as shown in Figure 5-6. Overflow from TLn not only sets TFn, but also reloads TLn with the contents of THn, which must be preset by software. The reload leaves THn unchanged. Mode 2 operation is the same for Timer 0 and Timer 1.

2003 Dec 8

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Philips P89LPC903, P89LPC902 user manual Mode, Tamod P89LPC901, TAMOD.7-1, TAMOD.0
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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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