Philips P89LPC903, P89LPC902 user manual P89LPC901/902/903 Power Reduction Modes

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Philips Semiconductors

User’s Manual - Preliminary -

 

 

 

 

 

 

POWER MONITORING FUNCTIONS

P89LPC901/902/903

 

 

Power Reduction Modes

 

 

The P89LPC901/902/903 supports three different power reduction modes as determined by SFR bits PCON.1-0 (see Table 7-2):

PMOD1

PMOD0

Description

(PCON.1)

(PCON.0)

 

0

0

Normal Mode (Default) - no power reduction.

 

 

 

0

1

Idle Mode. The Idle mode leaves peripherals running in order to allow them to activate the processor

when an interrupt is generated. Any enabled interrupt source or reset may terminate Idle mode.

 

 

 

 

 

 

 

Power down mode:

 

 

The Power down mode stops the oscillator in order to minimize power consumption.

 

 

The P89LPC901/902/903 exits Power down mode via any reset, or certain interrupts - brownout

 

 

Interrupt, keyboard, Real-time clock (system timer), watchdog, and comparator trips. Waking up by reset

 

 

is only enabled if the corresponding reset is enabled, and waking up by interrupt is only enabled if the

 

 

corresponding interrupt is enabled and the EA SFR bit (IEN0.7) is set.

 

 

In Power down mode the internal RC oscillator is disabled unless both the RC oscillator has been

 

 

selected as the system clock AND the RTC is enabled

 

 

In Power down mode, the power supply voltage may be reduced to the RAM keep-alive voltage VRAM.

 

 

This retains the RAM contents at the point where Power down mode was entered. SFR contents are not

 

 

guaranteed after VDD has been lowered to VRAM, therefore it is recommended to wake up the processor

1

0

via Reset in this situation. VDD must be raised to within the operating range before the Power down mode

is exited.

 

 

When the processor wakes up from Power down mode, it will start the oscillator immediately and begin

 

 

execution when the oscillator is stable. Oscillator stability is determined by counting 1024 CPU clocks

 

 

after start-up when one of the crystal oscillator configurations is used, or 256 clocks after start-up for the

 

 

internal RC or external clock input configurations.

 

 

Some chip functions continue to operate and draw power during Power down mode, increasing the total

 

 

power used during Power down. These include:

•Brownout Detect

•Watchdog Timer if WDCLK (WDCON.0) is ’1’.

•Comparator (Note: Comparator can be powered down separately with PCONA.5 set to ’1’ and comparator disabled);

•Real-time Clock/System Timer (and the crystal oscillator circuitry if this block is using it, unless RTCPD, i.e., PCONA.7 is ’1’).

 

 

Total Power down mode: This is the same as Power down mode except that the Brownout Detection

 

 

circuitry and the voltage comparators are also disabled to conserve additional power. Note that a

 

 

brownout reset or interrupt will not occur. Voltage comparator interrupts and Brownout interrupt cannot

 

 

be used as a wakeup source.The internal RC oscillator is disabled unless both the RC oscillator has

 

 

been selected as the system clock AND the RTC is enabled.

 

 

The following are the wakeup options supported:

1

1

• Watchdog Timer if WDCLK (WDCON.0) is ’1’. Could generate Interrupt or Reset, either one can wake

 

 

up the device

•Keyboard Interrupt

•Real-time Clock/System Timer (and the crystal oscillator circuitry if this block is using it, unless RTCPD, i.e., PCONA.7 is ’1’).

•Note: Using the internal RC-oscillator to clock the RTC during Power down may result in relatively high power consumption. Lower power consumption can be achieved by using an external low frequency clock when the Real-time Clock is running during Power down.

Table 7-2: Power Reduction Modes.

2003 Dec 8

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Contents Philips Semiconductors User ManualTable of Contents Power Monitoring Functions 103 P89LPC901/902/903 List of Figures P89LPC902 Pin ConfigurationsProduct comparison Logic SymbolsCPU Block Diagram P89LPC901High Performance Accelerated 2-clock 80C51 CPU Block Diagram P89LPC902Uart Block Diagram P89LPC903CIN1A Mnemonic PIN no Type Name and FunctionKBI4 KBI5XTAL1 P3.1KBI0 CMP2CIN2A KBI2TxD P1.0P1.1 RxDSpecial Function Registers Table P89LPC901 Special Function RegistersBit Functions and Addresses Hex Special Function Registers Table P89LPC902 CMP1 Cmpref CIN1A KB2 KB0 KB6 KB5 KB4 A7H PRE2 PRE1 PRE0 Wdrun Wdtof Special Function Registers Table P89LPC903 F7H Psth PCH Pkbih TRIM.5 TRIM.4 TRIM.3 TRIM.2 TRIM.1 TRIM.0 WDCON# Data P89LPC901/902/903 Memory OrganizationSFR CodeGeneral Description Clock Definitions Enhanced CPUCPU Clock Oscclk Low Speed Oscillator Option P89LPC901Oscillator Option Selection- P89LPC901 Clock Output P89LPC901On-Chip RC oscillator Option Watchdog Oscillator Option BIT Symbol FunctionExternal Clock Input Option P89LPC901 TrimMed freq High freqLow freq DivmAtchdog CPU Clock Cclk Modification Divm Register CPU Clock Cclk Wakeup DelayL K O sc illa to rP89LPC901/902/903 Low Power Select P89LPC901 P89LPC901/902/903 Interrupt Priority Structure Summary of Interrupts P89LPC901 Description Flag Bits Address Enable Bits Priority RankingInterrupt Arbitration Summary of Interrupts P89LPC902 DescriptionExternal Interrupt Pin Glitch Suppression P89LPC901/902/903 External Interrupt InputsTF1 ET1 TI & RI/RI ES/ESR Quasi-Bidirectional Output Configuration Port ConfigurationsNumber of I/O Pins Available Clock Source Reset Option RSTQuasi-Bidirectional Output Open Drain Output ConfigurationP89LPC901/902/903 Input-Only Configuration Push-Pull Output ConfigurationPort 0 Analog Functions Port Output Configuration P89LPC901 Additional Port FeaturesPort Output Configuration P89LPC902 Port Output Configuration P89LPC903Ports Ports TMOD.7 TmodTMOD.6 TMOD.3Tamod P89LPC901 ModeTAMOD.7-1 TAMOD.0P89LPC901/902/903 Mode Mode 6 P89LPC901Tcon Pclk Timer/Counter 0 or 1 in Mode 0 13-bit counterTimer Overflow toggle output P89LPC901 Pclk TL0TR0 ENT0 Pclk TH0 Timers 0 Real-time Clock Source Real-time clock/system timer Block DiagramFOSC2 FOSC1 FOSC0 RTCS10 Real-time Clock/System Timer Clock Source P89LPC901UCFG1.2 UCFG1.1 UCFG1.0 Cclk Frequency RTC Clock Frequency XclkReal-time Clock/System Timer Clock Source P89LPC902/903 Reset Sources Affecting the Real-time ClockChanging RTCS1-0 Real-time Clock Interrupt/Wake UpRtccon Brownout Detection Brownout Options Power-On DetectionPower Reduction Modes P89LPC901/902/903 Power Reduction ModesPcon Pcona Power Monitoring Functions Uart P89LPC903 Baud Rate Generator and Selection P89LPC901/902/903 SFR SpaceUpdating the BRGR1 and BRGR0 SFRs SFR Locations for UARTsFraming Error Break DetectBrgcon Scon Sstat More About Uart ModeSerial Port Mode 0 Double Buffering Must Be Disabled FE and RI when SM2 = 1 in Modes 2 Framing Error and RI in Modes 2 and 3 with SM2 =P89LPC901/902/903 More About Uart Modes 2 PCON.6 RB8 SMOD0Double Buffering in Different Modes P89LPC901/902/903 Double BufferingTransmission with and without Double Buffering 9th Bit Bit 8 in Double Buffering Modes 1, 2Automatic Address Recognition Multiprocessor CommunicationsUart P89LPC903 Uart P89LPC903 Block Diagram of Reset Power-On reset code executionRstsrc CMPn Comparator ConfigurationComparator Input and Output Connections P89LPC901 Internal Reference Voltage Comparator InterruptCmpref Comparator Configuration Example Comparator and Power Reduction ModesKBPATN.5,4 KbpatnKbmask KbconKBMASK.6 KBMASK.7KBMASK.3 KBMASK.2Keypad Interrupt KBI Watchdog timer configuration Watchdog FunctionWdte Wdse Function Feed Sequence Wdcon P89LPC901/902/903 Watchdog Timeout Values Prescaler Reset PclkWDCONA7H Power down operation P89LPC901/902/903 Watchdog Timer in Timer ModeWatchdog Clock Source PrescalerWatchdog Timer Watchdog Timer Watchdog Timer Software Reset Dual Data PointersAUXR1 MOVCA, @A+DPTR MOVXA, @DPTRMOVX@DPTR, a Using Flash as data storage FeaturesGeneral description Introduction to IAP-LiteFlash Program Memory Fmcon C-language routine to erase/program all or part of a Accessing additional flash elementsErase-programming additional flash elements Reading additional flash elementsUCFG1 Fmadrl C-language routine to read a flash element User Configuration BytesP89LPC901 UCFG1SECx User Security BytesBoot Status P89LPC901/902/903 Boot VectorBootvec BootstatLogical ArithmeticData Transfer Mnemonic Description Bytes Cycles Hex CodeBranching BooleanB8-BF RetiD8-DF MiscellaneousRevision History 108 Index Dual Data Pointers Port 0 12, 14 SFR 113 P89LPC901/902/903

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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