Philips P89LPC906 SFR Space, Baud Rate Generator and Selection, Updating the BRGR1 and BRGR0 Sfrs

Page 60

Philips Semiconductors	User’s Manual - Preliminary -

UART	P89LPC906/907/908
SFR SPACE

The UART SFRs are at the following locations:

Table 8-1: SFR Locations for UARTs

Register	Description	SFR Location

PCON	Power Control	87H

SCON	Serial Port (UART) Control	98H

SBUF	Serial Port (UART) Data Buffer	99H

SADDR	Serial Port (UART) Address	A9H

SADEN	Serial Port (UART) Address Enable	B9H

SSTAT	Serial Port (UART) Status	BAH

BRGR1	Baud Rate Generator Rate High Byte	BFH

BRGR0	Baud Rate Generator Rate Low Byte	BEH

BRGCON	Baud Rate Generator Control	BDH

BAUD RATE GENERATOR AND SELECTION

The enhanced UART has an independent Baud Rate Generator. The baud rate is determined by a value programmed into the BRGR1 and BRGR0 SFRs. The UART can use either Timer 1 or the baud rate generator output as determined by BRGCON.2- 1 (see Figure 8-2). Note that Timer T1 is further divided by 2 if the SMOD1 bit (PCON.7) is cleared. The independent Baud Rate Generator uses CCLK.

UPDATING THE BRGR1 AND BRGR0 SFRS

The baud rate SFRs, BRGR1 and BRGR0 must only be loaded when the Baud Rate Generator is disabled (the BRGEN bit in the BRGCON register is ’0’). This avoids the loading of an interim value to the baud rate generator. (CAUTION: If either BRGR0 or BRGR1 is written when BRGEN = 1, the result is unpredictable.)

Table 8-2: Baud Rate Generation for UART

	SCON.7	SCON.6	PCON.7	BRGCON.1	Receive/Transmit Baud Rate for UART
	(SM0)	(SM1)	(SMOD1)	(SBRGS)	Receive/Transmit Baud Rate for UART
	(SM0)	(SM1)	(SMOD1)	(SBRGS)

	0	0	X	X	CCLK/16

			0	0	CCLK/(256-TH1)64

	0	1	1	0	CCLK/(256-TH1)32

			X	1	CCLK/((BRGR1,BRGR0)+16)

	1	0	0	X	CCLK/32

			1	X	CCLK/16
			1	X	CCLK/16

			0	0	CCLK/(256-TH1)64

	1	1	1	0	CCLK/(256-TH1)32

			X	1	CCLK/((BRGR1,BRGR0)+16)

2003 Dec 8

60

Image 60

Contents User Manual Table of Contents Brownout Detection Power-On Detection Power Reduction Modes Power-On reset code execution103 List of Figures List of Figures PIN Configurations P89LPC906Logic Symbols Product ComparisonBlock Diagram P89LPC906 KB Code FlashCPU Oscillator DividerBlock Diagram P89LPC907 UartByte Data RAM ClockBlock Diagram P89LPC908 Data RAM PortPIN Descriptions P89LPC906 PIN Descriptions P89LPC907 P1.0TxD P1.2PIN Descriptions P89LPC908 Keyboard Input P1.0 P1.5P1.1 RxDSpecial function registers Special function registers table P89LPC906MSB 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 Memory Organization DataSFR CodeEnhanced CPU Clock DefinitionsCPU Clock Oscclk LOW Speed Oscillator Option P89LPC906Oscillator Option SELECTION- P89LPC906 Clock Output P89LPC906ON-CHIP RC Oscillator Option Watchdog Oscillator OptionCPU Clock Cclk Wakeup Delay BIT Symbol FunctionExternal Clock Input Option P89LPC906 CPU Clock Cclk Modification Divm RegisterLOW Power Select P89LPC906 High freqMed freq Low freqCPU Clocks Flag Bits Address Enable Bits Priority Ranking Interrupt Priority StructureSummary of Interrupts P89LPC906 Description Interrupt ArbitrationExternal Interrupt Inputs External Interrupt PIN Glitch SuppressionSummary of Interrupts P89LPC907,P89LPC908 Description TI & RIBopd EBO Rtcf Kbif Interrupts Port Configurations QUASI-BIDIRECTIONAL Output ConfigurationNumber of I/O Pins Available Clock Source Reset Option RSTOpen Drain Output Configuration Port latch dataINPUT-ONLY Configuration PUSH-PULL Output ConfigurationPort 0 Analog Functions Strong Port latch data Port pin Input data Glitch rejectionPort Output Configuration P89LPC906 Port Output Configuration P89LPC907Port Output Configuration P89LPC908 Ports Ports Tmod TMOD.7TMOD.6 TMOD.3Overflows. Mode ModeTamod P89LPC907 TAMOD.7-1Tcon Pclk T0C/T = Overflow TLn THn TFn Interrupt T0 PinT0C/T = Overflow THn TFnTimer Overflow Toggle Output P89LPC907 Pclk TL0TR0 ENT0 Pclk TH0 Timers 0 REAL-TIME Clock Source FOSC2 FOSC1 FOSC0 RTCS10 UCFG1.2 UCFG1.1 UCFG1.0 Cclk Frequency RTC Clock FrequencyXclk Divm CclkRC Oscillator/DIVM WDT Oscillator/DIVMUndefined External clock/DIVMReset 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 Uart ModesSFR Space Baud Rate Generator and SelectionUpdating the BRGR1 and BRGR0 Sfrs SFR Locations for UARTsFraming Error Break DetectBrgcon Scon More about Uart Mode SstatSerial Port Mode 0 Double Buffering Must Be Disabled Framing Error and RI in Modes 2 and 3 with SM2 = FE and RI when SM2 = 1 in Modes 2More about Uart Modes 2 PCON.6 RB8 SMOD0Double Buffering Double Buffering in Different Modes9TH BIT BIT 8 in Double Buffering Modes 1, 2 Transmission with and without Double BufferingMultiprocessor Communications Automatic Address RecognitionUart Uart POWER-ON Reset Code Execution Block Diagram of ResetRstsrc Comparator Configuration Comparator and Power Reduction Modes Internal Reference VoltageComparator Interrupt CIN1A CO1 CMP1 CmprefComparator Configuration Example Analog Comparators Kbpatn KbconKbmask Watchdog timer configuration Watchdog FunctionWdte Wdse Function Feed Sequence Wdcon P89LPC906/907/908 Watchdog Timeout Values PRE2-PRE0Watchdog Timer in Timer Mode Prescaler Reset PclkWatchdog Control registerPower Down Operation Watchdog Clock SourcePrescaler CLKWatchdog Timer Watchdog Timer Software Reset Dual Data PointersAUXR1 MOVCA, @A+DPTR Move code byte relative to Dptr to the accumulatorMOVXA, @DPTR MOVX@DPTR, aFeatures Using Flash AS Data StorageGeneral Description Introduction to IAP-LITEFlash Program Memory Fmcon Accessing Additional Flash Elements Assembly language routine to erase/program all or part of aERASE-PROGRAMMING Additional Flash Elements Reading Additional Flash ElementsUCFG1 Fmadrl Conf User Configuration Bytes UCFG1P89LPC906 User Security Bytes SECxAddress xxxxh Unprogrammed value 00hBootvec BootstatArithmetic LogicalMnemonic Description Bytes Cycles Hex Code Data TransferBoolean BranchingReti B8-BFD8-DF Miscellaneous2003 Dec Initial release 104 Index Dual Data Pointers Port 0 12, 13 SFR 109 P89LPC906/907/908