CS5531/32/33/34 - Eshop-Rychle.cz

CS5531/32/33/34FRS (WR3-WR0)Clock Cycles(First Conversion)0 1010 17848 ± 8 51200 1011 28088 ± 8 102400 1100 48568 ± 8 204801 0000 107434 ± 10 491521 0001 205738 ± 10 983041 0010 402346 ± 10 1966081 0011 795562 ± 10 3932161 0100 1581994 ± 10 7864321 1000 2966 ± 10 15361 1001 15274 ± 10 30721 1010 21418 ± 10 61441 1011 33706 ± 10 122881 1100 58282 ± 10 24576Table 2. Conversion Timing for Continuous Mode2.6.3. Examples of Using CSRs to PerformConversions and CalibrationsAny time a calibration or conversion command isissued (C, MC, and CC2-CC0 bits must be properlyset), the CSRP2-CSRP0 bits in the command byteare used as pointers to address one of the Setups inthe channel-setup registers (CSRs). Table 3 detailsthe address decoding of the pointer the bits.(CSRP2-CSRP0) CSR Location Setup000 CSR #1 1001 CSR #1 2010 CSR #2 3011 CSR #2 4100 CSR #3 5101 CSR #3 6110 CSR#4 7111 CSR #4 8Table 3. Command Byte PointerClock Cycles(All OtherConversions)The examples that follow detail situations that auser might encounter when acquiring a conversionor calibrating the converter. These examples assumethat the CSRs are programmed with the followingphysicalchannelorder:4,1,1,2,4,3,4,4.A physical channel is defined as the actual inputchannel (AIN1 to AIN4) to which an external signalis connected.Example 1: Single conversion using Setup 1. Thecommand issued is ‘10000000’. This instructs theconverter to perform a single conversion referencingSetup1(CSRP2-CSRP0=‘000’)In this example,Setup 1 points to physical channel 4. Afterthe command is received and decoded, the ADCperforms a conversion on physical channel 4 andSDO falls to indicate that the conversion is complete.To read the conversion, 40 SCLKs are thenrequired. Once the conversion data has been read,the serial port returns to the command mode.Example 2: Continuous conversions using Setup 3.The command issued is ‘11010000’. This instructsthe converter to perform continuous conversionsreferencingSetup3(CSRP2-CSRP0=‘010’). Inthis example, Setup 3 points to physical channel 1.After the command is received and decoded, theADC performs a conversion on physical channel 1and SDO falls to indicate that the conversion iscomplete. The user now has three options. The usercan acquire the conversion and remain in thismode, acquire the conversion and exit this mode, orignore the conversion and wait for a new conversionat the next update interval, as detailed in thecontinuous conversion section.Example 3: Calibration using Setup 4. This exampleassumes that the OGS bit in the ConfigurationRegister is set to ‘0’. The command issued is‘10011001’. This instructs the converter to performa self offset calibration referencing Setup 4(CSRP2 - CSRP0 = ‘011’). In this example, Setup4 points to physical channel 2. After the commandis received and decoded, the ADC performs a selfoffset calibration on physical channel 2 and SDOfalls to indicate that the calibration is complete. Toperform additional calibrations, more commandsmust be issued.Note:The CSRs need not be written. If they are notDS289PP5 37