電子元器件應(yīng)用-Interfacing the TLC561

1、Interfacing the TLC5618ADigital-to-Analog Converter to theApplication ReportTMS320C203 DSPLiterature Number: SLAA033July 1998IMPORTANT NOTICETexas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinueany product or service without notice, and adv

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3、arranty, patent infringement, and limitation of liability.TI warrants performance of its semiconductor products to the specifications applicable at the time of sale inaccordance with TIs standard warranty. Testing and other quality control techniques are utilized to the extentTI deems necessary to s

4、upport this warranty. Specific testing of all parameters of each device is not necessarilyperformed, except those mandated by government requirements.CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OFDEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“C

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8、irdpartys products or services does not constitute TIs approval, warranty or endorsement thereof.Copyright © 1998, Texas Instruments IncorporatedContents1Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9、 . . . . . . . . . . . . . . . . . . 12TLC5618A Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Operational Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.1Signal Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.2Reference Voltage Inputs. . . . . . . . . . . . . . .

11、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.3Input Data Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54The DAC/DSP System. . . .

12、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65The DSP Serial Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13、 . . . . . . 75.1DSP Internal Serial Port Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86Software Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14、. . . . . . . . . . . . . . . . . . . . 96.1Flowchart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106.2Program Listing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15List of Figures12346Application Schematic

16、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Package Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17、. . . . . . . . . . . . . . 2Functional Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Timing Diagram for TLC5618A Only. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

18、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Internal DSP Serial Port Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8TLC5618A to TMS320C203 80 MHz DSP Interface Program Flow Chart. . . . . . . .

19、. . . . . . . . . . . . . . . . . . . . . . . 10List of Tables1234Terminal Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Program Modes. . . . . . . . . . . . . . . . . . . . . .

20、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5DSP/DAC Interconnection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6DSP Seria

21、l Port Signals and Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Interfacing the TLC5618A Digital-to-Analog Converter to the TMS320C203 DSPiiiivSLAA033Software OverviewSoftware OverviewThis interface program gene

22、rates a triangle waveform from DSP to TLC5618A.Figure 6 shows the program flowchart.The C203 CLKINX2 frequency is 80 MHz, the CPU CLK for the C203 DSP is40 MHz, SCLK for the TLC5618A is driven by CLKX, which is 20 MHz.The program starts with a common initialization procedure for the DSP followedby t

23、he initialization of the serial port.The following steps initialize the DSP.1.Disable the global interrupts.2.Set the data page pointer to 0h.The next two steps initialize the serial port.3.Set the synchronous serial port control register to 0C00Eh(SSPCR=0C00Eh)The individual bits within the SSPCR n

24、ow contain the following functions:The frame sync mode bit is set to 1 (FSM=1) to allow burst modeoperation.The clock mode bit is set to 1 (MCM=1) to set the transmit clock CLKXto1/2 of the DSP master clock of 40 MHz (CLKX frequency = 20 MHz)The transmit mode bit is set to 1 (TXM=1) to generate the

25、frame syncinternally as required for the data transfer initiation. FSX is nowprogrammed as an output.The FREE and SOFT bits are set to 1. The clock continues to run atbreakpoint.4.Set the synchronous serial port control register to 0C03Eh(SSPCR=0C03Eh)Writing 1s to the transmitter reset field (XRST)

26、 and to the receiver reset field(RRST) activates the serial port transmitter and receiver.The program executes the following steps:1.Initializes the C203 DSP2.Initializes the serial port3.DSP generates a triangle waveform to TLC5618A.4.After obtaining all waveform(AR7=0), the DSP exits the triangle_

27、wavesubroutine.The data is now available for use in user defined functions (algorithms).Interfacing the TLC5618A Digital-to-Analog Converter to the TMS320C203 DSP96Software OverviewProgram Listing; *; *(C) COPYRIGHT TEXAS INSTRUMENTS, INC. 1998*; *;*; *; *File: AC5618DA.ASM Main routine*; *; *Writte

28、n By: David Quach*;*.title ”TLV5618A DAC Interface routine”;*; This routine allows the C2O3EVM to interface with a DAC on the; Serial port of the DSP.;Program Bits D15 D12 Function;D15D14D13D12 |; 1| Write to latch A from DSP and latch B;| updated with buffer latch data.; 0 0| Write to latch B and d

29、ouble buffer.; 0 1| Write to double buffer latch only.; 0| 12.5 µs setting time.; 1| 2.5 µs setting time.; 0| Powererup operation.; 1| Power down mode.;.mmregsSDTR .set0fff0hSSPCR .set0fff1hLatch_B .set061h.datanum_samples.set8; (Number of intervals per cycle) / 2codes_per_interval .set 51

30、2; (4096 counts) / (num_samples)num_waves.set10; Number of triangle waveSoftware Overview.ps.textstart:SETCLDPCLRCSPLKOUTSPLKOUTlarINTM#0INTM#0c00eh,temp0temp0, SSPCR#0c03eh, temp0temp0, SSPCRAR7,#num_waves1; (AR7) = #(num_waves1); XRST=RRST=1 reset the receiver and; FREE=SOFT=TXM=MCM=FSM=1; disable

31、 global interrupts; set data page pointer1000h; Starting Program Address = 1000h; Initialize Serial Port; transmitter interface; DSP will generate a triangle wave to DAC Latch A and double buffer,; while ; latch A is beginning from 0h, increment by 200h (512); to FFFh (4095). Then decrease to 0h, de

32、crement of 200h (512).; The process is opposite for double buffer. It begins from FFFh (4095); decrement by 200h (512), to 0h. Then increase to FFFh (4095); increment of 200h (512)* Initial Start PointlarsarLARsaroutrptnopoutrptnopLARTriangle_wave:marmarsaroutrptnopmarmarsarout12*, AR2*0+AR2, Latch_

33、ALatch_A, SDTR*, AR4*0; Select AR4; (AR4) = (AR4)(AR0) = (5E00h); Send (AR4) to double bufferLatch_A, SDTR#99; 2.5 µs/25 ns = 100 at CLKOUT1=40MHz; Wait 2.5 ms for output settling timeAR0, #codes_per_interval1 ;AR0=#(codes/interval1) = 511AR4, #5FFFhAR2, #0C000hAR2, Latch_A; (AR4) = #5FFFh; (AR

34、2) = #0C000h; Write 0 to latch AAR4, Double_Buffer ; write full scale to double buffer* Send the initial data to DACDouble_Buffer, SDTR#99; 2.5 µs/25 ns = 100 at CLKOUT1=40 MHz; Wait 2.5 ms for output settling timeAR4, Double_BufferDouble_Buffer, SDTR#99; 2.5 µs/25 ns = 100 ;CLKOUT1=40 MHz

35、; wait 2.5 µs for output settling time; Select AR2; (AR2) = (AR2) + (AR0) = (C1FFh); Send (AR2) to latch ASLAA033Software Overviewrpt#99; 2.5 µs/25 ns = 100 ;CLKOUT1=40MHznopLARAR5, #num_samples2; (AR5) = #(num_samples2)LARAR0, #codes_per_interval; (AR0)= codes/intervalup:mar*, AR4; select

36、 AR4mar*0; (AR4) = (AR4)(AR0)sarAR4, Double_Buffer ; write (AR4) to double bufferoutDouble_Buffer, SDTRrpt#99; 2.5 µs/25 ns = 100 CLKOUT1=40 MHznopmar*, AR2; select AR2mar*0+; (AR2)=(AR2)+(AR0)sarAR2, Latch_A; write (AR2) to latch AoutLatch_A, SDTRrpt#99; 2.5 µs/25 ns = 100 CLKOUT1=40 MHzn

37、opmar*, AR5; select AR5BANZup; IF AR5 <>0, GO BACK TO UP, AND (AR5)1LARAR5, #num_samples2 ;(AR5)=#(num_samples2)down:mar*, AR4; select AR4mar*0+; (AR4) = (AR4) + (AR0)sarAR4, Double_Buffer ; write (AR4) to double bufferoutDouble_Buffer, SDTRrpt#99; 2.5 µs/25 ns = 100 CLKOUT1=40 MHznopmar*, AR2; select AR2mar*0; (AR2) = (AR2) (AR0)sarAR2, Latch_A; write (AR2) to latch AoutLatch_A, SDTRrpt#99; 2.5