Texas Instruments TMS320C642X manual 12 I2C Prescaler Register Icpsc, Ipsc

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Registers

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3.12 I2C Prescaler Register (ICPSC)

The I2C prescaler register (ICPSC) is used for dividing down the I2C input clock to obtain the desired prescaled module clock for the operation of the I2C.

The IPSC bits must be initialized while the I2C is in reset (IRS = 0 in ICMDR). The prescaled frequency takes effect only when the IRS bit is changed to 1. Changing the IPSC value while IRS = 1 has no effect.

The I2C prescaler register (ICPSC) is shown in Figure 26 and described in Table 19.

Figure 26. I2C Prescaler Register (ICPSC)

31				16
	Reserved

		R-0
15	8	7		0

	Reserved			IPSC

	R-0			R/W-0

LEGEND: R/W = Read/Write; R = Read only; -n= value after reset

			Table 19. I2C Prescaler Register (ICPSC) Field Descriptions

Bit	Field	Value		Description

31-8	Reserved	0		These reserved bit locations are always read as zeros. A value written to this field has no effect.

7-0	IPSC	0-FFh		I2C prescaler divide-down value. IPSC determines how much the I2C input clock is divided to create the
				I2C prescaled module clock:
				I2C clock frequency = I2C input clock frequency/(IPSC + 1)
				Note: IPSC must be initialized while the I2C is in reset (IRS = 0 in ICMDR).

38	Inter-Integrated Circuit (I2C) Peripheral	SPRUEN0D –March 2011
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Contents Users Guide Submit Documentation Feedback Revision History Appendix aList of Figures List of Tables Read This First Purpose of the Peripheral FeaturesFeatures Not Supported Functional Block Diagram Industry Standards Compliance StatementBus Structure Multiple I2C Modules ConnectedClocking Diagram for the I2C Peripheral Clock GenerationInput and Output Voltage Levels Signal DescriptionsClock Synchronization Start and Stop Conditions Data ValiditySerial Data Formats 1 7-Bit Addressing FormatFree Data Format Using a Repeated Start Condition2 10-Bit Addressing Format ACKOperating Modes Operating Mode DescriptionEndianness Considerations Operating Modes of the I2C PeripheralNack Bit Generation Nack Bit GenerationWays to Generate a Nack Bit I2C Peripheral Condition Basic OptionalArbitration Procedure Between Two Master-Transmitters ArbitrationHardware Reset Considerations Reset ConsiderationsSoftware Reset Considerations InitializationConfiguring the I2C in Slave Receiver and Transmitter Mode Peripheral Architecture DMA Events Generated by the I2C Peripheral Power ManagementInterrupt Support Acronym Register Description Emulation ConsiderationsInter-Integrated Circuit I2C Registers Oaddr I2C Own Address Register IcoarI2C Own Address Register Icoar Field Descriptions Bit Field Value DescriptionSCD Icxrdy Icrrdy Ardy Nack I2C Interrupt Mask Register IcimrI2C Interrupt Mask Register Icimr Field Descriptions AASSdir Nacksnt Rsfull Xsmt I2C Interrupt Status Register IcstrI2C Interrupt Status Register Icstr Field Descriptions SdirBit Field AD0An acknowledge bit ACK has been sent by the receiver 2 I2C Clock High-Time Divider Register Icclkh I2C Clock Divider Registers Icclkl and Icclkh1 I2C Clock Low-Time Divider Register Icclkl IcclIcdc I2C Data Count Register IccntI2C Data Count Register Iccnt Field Descriptions I2C Data Receive Register Icdrr Field Descriptions I2C Data Receive Register IcdrrI2C Slave Address Register Icsar I2C Slave Address Register Icsar Field DescriptionsI2C Data Transmit Register Icdxr I2C Data Transmit Register Icdxr Field DescriptionsI2C Mode Register Icmdr I2C Mode Register Icmdr Field DescriptionsRM bit is dont care Icmdr Bit Bus Activity DescriptionHow the MST and FDF Bits Affect the Role of TRX Bit I2C State Function of TRX BitIntcode 10 I2C Interrupt Vector Register IcivrI2C Interrupt Vector Register Icivr Field Descriptions Ignack BCM R/W-0 R/W-1 11 I2C Extended Mode Register IcemdrI2C Extended Mode Register Icemdr Field Descriptions IgnackIpsc 12 I2C Prescaler Register IcpscI2C Prescaler Register Icpsc Field Descriptions Type 13 I2C Peripheral Identification Register ICPID114 I2C Peripheral Identification Register ICPID2 I2CDocument Revision History Reference Additions/Modifications/DeletionsRfid Products ApplicationsDSP TI E2E Community Home