Philips P89LPC906, P89LPC908, P89LPC907 user manual Software Reset, Dual Data Pointers, AUXR1

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Philips Semiconductors	User’s Manual - Preliminary -

ADDITIONAL FEATURES	P89LPC906/907/908
13. ADDITIONAL FEATURES

The AUXR1 register contains several special purpose control bits that relate to several chip features. AUXR1 is described in Figure 13-1.

AUXR1

7

6

5

4

3

2

1

0

Address: A2h

CLKLP

EBRR

-

-

SRST

0

-

DPS

Not bit addressable

Reset Source(s): Any reset

Reset Value: 000000x0B

BIT

SYMBOL

FUNCTION

AUXR1.7

CLKLP

Clock Low Power Select. When set, reduces power consumption in the clock circuits. Can

be used when the clock frequency is 8MHz or less. After reset this bit is cleared to support

up to 12MHz operation (P89LPC906).

AUXR1.6

EBRR

UART Break Detect Reset Enable. If ’1’, UART Break Detect will cause a chip reset

(P89LPC908). When writing to this register on the P89LPC906 or P89LPC907 devices,

this bit position should be written with a zero.

AUXR1.5

-

Reserved

AUXR1.4

-

Reserved

AUXR1.3

SRST

Software Reset. When set by software, resets the P89LPC906/907/908 as if a hardware

reset occurred.

AUXR1.2

0

This bit contains a hard-wired 0. Allows toggling of the DPS bit by incrementing AUXR1,

without interfering with other bits in the register.

AUXR1.1

-

Not used. Allowable to set to a "1" .

AUXR1.0

DPS

Data Pointer Select. Chooses one of two Data Pointers.

Figure 13-1: AUXR1 Register

SOFTWARE RESET

The SRST bit in AUXR1 gives software the opportunity to reset the processor completely, as if an external reset or watchdog reset had occurred. If a value is written to AUXR1 that contains a 1 at bit position 3, all SFRs will be initialized and execution will resume at program address 0000. Care should be taken when writing to AUXR1 to avoid accidental software resets.

DUAL DATA POINTERS

The dual Data Pointers (DPTR) adds to the ways in which the processor can specify the address used with certain instructions. The DPS bit in the AUXR1 register selects one of the two Data Pointers. The DPTR that is not currently selected is not accessible to software unless the DPS bit is toggled.

Specific instructions affected by the Data Pointer selection are:

•	INC	DPTR	Increments the Data Pointer by 1.
•	JMP	@A+DPTR	Jump indirect relative to DPTR value.

2003 Dec 8

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Contents User Manual Table of Contents Power-On reset code execution Brownout Detection Power-On Detection Power Reduction Modes103 List of Figures List of Figures P89LPC906 PIN ConfigurationsProduct Comparison Logic SymbolsOscillator Divider Block Diagram P89LPC906KB Code Flash CPUClock Block Diagram P89LPC907Uart Byte Data RAMData RAM Port Block Diagram P89LPC908PIN Descriptions P89LPC906 P1.2 PIN Descriptions P89LPC907P1.0 TxDRxD PIN Descriptions P89LPC908Keyboard Input P1.0 P1.5 P1.1Special function registers table P89LPC906 Special function registersMSB LSB Hex Special function registers table P89LPC907 CMP1 Cmpref TRIM.5 TRIM.4 TRIM.3 TRIM.2 TRIM.1 TRIM.0 WDCON# Special function registers table P89LPC908 KB2 KB6 KB5 KB4 TL0 Code Memory OrganizationData SFRLOW Speed Oscillator Option P89LPC906 Enhanced CPUClock Definitions CPU Clock OscclkWatchdog Oscillator Option Oscillator Option SELECTION- P89LPC906Clock Output P89LPC906 ON-CHIP RC Oscillator OptionCPU Clock Cclk Modification Divm Register CPU Clock Cclk Wakeup DelayBIT Symbol Function External Clock Input Option P89LPC906Low freq LOW Power Select P89LPC906High freq Med freqCPU Clocks Interrupt Arbitration Flag Bits Address Enable Bits Priority RankingInterrupt Priority Structure Summary of Interrupts P89LPC906 DescriptionTI & RI External Interrupt InputsExternal Interrupt PIN Glitch Suppression Summary of Interrupts P89LPC907,P89LPC908 DescriptionBopd EBO Rtcf Kbif Interrupts RST Port ConfigurationsQUASI-BIDIRECTIONAL Output Configuration Number of I/O Pins Available Clock Source Reset OptionPort latch data Open Drain Output ConfigurationStrong Port latch data Port pin Input data Glitch rejection INPUT-ONLY ConfigurationPUSH-PULL Output Configuration Port 0 Analog FunctionsPort Output Configuration P89LPC906 Port Output Configuration P89LPC907Port Output Configuration P89LPC908 Ports Ports TMOD.3 TmodTMOD.7 TMOD.6TAMOD.7-1 Overflows. ModeMode Tamod P89LPC907Tcon THn TFn PclkT0C/T = Overflow TLn THn TFn Interrupt T0 Pin T0C/T = OverflowTimer Overflow Toggle Output P89LPC907 Pclk TL0TR0 ENT0 Pclk TH0 Timers 0 REAL-TIME Clock Source Divm Cclk FOSC2 FOSC1 FOSC0 RTCS10UCFG1.2 UCFG1.1 UCFG1.0 Cclk Frequency RTC Clock Frequency XclkExternal clock/DIVM RC Oscillator/DIVMWDT Oscillator/DIVM UndefinedReset Sources Affecting the REAL-TIME Clock Changing RTCS1-0REAL-TIME Clock INTERRUPT/WAKE UP Rtccon REAL-TIME CLOCK/SYSTEM Timer Brownout Detection POWER-ON Detection Power Reduction ModesBrownout Options Power Reduction Modes Pcon Pcona Power Monitoring Functions Modes UartSFR Locations for UARTs SFR SpaceBaud Rate Generator and Selection Updating the BRGR1 and BRGR0 SfrsFraming Error Break DetectBrgcon Scon Sstat More about Uart ModeSerial Port Mode 0 Double Buffering Must Be Disabled PCON.6 RB8 SMOD0 Framing Error and RI in Modes 2 and 3 with SM2 =FE and RI when SM2 = 1 in Modes 2 More about Uart Modes 2Double Buffering in Different Modes Double BufferingTransmission with and without Double Buffering 9TH BIT BIT 8 in Double Buffering Modes 1, 2Automatic Address Recognition Multiprocessor CommunicationsUart Uart Block Diagram of Reset POWER-ON Reset Code ExecutionRstsrc Comparator Configuration CIN1A CO1 CMP1 Cmpref Comparator and Power Reduction ModesInternal Reference Voltage Comparator InterruptComparator Configuration Example Analog Comparators Kbcon KbpatnKbmask Watchdog timer configuration Watchdog FunctionWdte Wdse Function Feed Sequence Wdcon PRE2-PRE0 P89LPC906/907/908 Watchdog Timeout ValuesControl register Watchdog Timer in Timer ModePrescaler Reset Pclk WatchdogCLK Power Down OperationWatchdog Clock Source PrescalerWatchdog Timer Watchdog Timer Software Reset Dual Data PointersAUXR1 MOVX@DPTR, a MOVCA, @A+DPTRMove code byte relative to Dptr to the accumulator MOVXA, @DPTRIntroduction to IAP-LITE FeaturesUsing Flash AS Data Storage General DescriptionFlash Program Memory Fmcon Assembly language routine to erase/program all or part of a Accessing Additional Flash ElementsERASE-PROGRAMMING Additional Flash Elements Reading Additional Flash ElementsUCFG1 Fmadrl Conf User Configuration Bytes UCFG1P89LPC906 Unprogrammed value 00h User Security BytesSECx Address xxxxhBootstat BootvecLogical ArithmeticData Transfer Mnemonic Description Bytes Cycles Hex CodeBranching BooleanMiscellaneous RetiB8-BF D8-DF2003 Dec Initial release 104 Index Dual Data Pointers Port 0 12, 13 SFR 109 P89LPC906/907/908