Texas Instruments TMS320F28004 Series, Manual

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4 Silicon Revision A Usage Notes and Advisories
This section lists the usage notes and advisories for this silicon revision.
4.1 Silicon Revision A Usage Notes
Silicon revision-applicable usage notes have been found on a later silicon revision. For more details, see Silicon
Revision B Usage Notes .
4.2 Silicon Revision A Advisories
Silicon revision-applicable advisories have been found on a later silicon revision. For more details, see Silicon
Revision B Advisories .
Advisory Analog Subsystem: Software Configuration for Shared Reference Pins
Revisions Affected
0, A
Details Smaller pin-count packages of the F28004x device family have combined VREFHI pins.
Software configuration bits are provided in the ANAREFPP register to disable all but one
of the ganged references. This allows correct operation of internal reference mode in
these circumstances. On production (TMS) devices, the Boot ROM will write these bits,
and no further action will be required from the user. However, on some TMX devices, this
write will not occur.
Workaround For TMX devices, the user should do the following writes one time before trying to
configure the references for internal reference mode:
• 100-pin PZ package: The value 0x0002 should be written to ANAREFPP.
• 64-pin PM package: The value 0x0003 should be written to ANAREFPP.
• 56-pin RSH package: The value 0x0003 should be written to ANAREFPP.
Advisory Analog Trim of Some TMX Devices
Revisions Affected
0, A
Details Some TMX samples may not have analog trims programmed. This could degrade the
performance of the ADC, buffered DAC, internal oscillators, PGA, and internal voltage
regulator. A value of all zeros in these trim registers will have the following impact.
TRIM REGISTER
IMPACT OF TRIM VALUE EQUAL TO
ZERO
ADC offset AdcaRegs.ADCOFFTRIM Degraded performance of the ADC offset
error specification.
AdcbRegs.ADCOFFTRIM
AdccRegs.ADCOFFTRIM
ADC reference AnalogSubsysRegs.ANAREFTRIMA Degraded performance of the ADC for all
specifications. No workaround available.
AnalogSubsysRegs.ANAREFTRIMB
AnalogSubsysRegs.ANAREFTRIMC
ADC linearity AdcaRegs.ADCINLTRIM2-3 Degraded INL and DNL specifications of
the ADC. No workaround available.
AdcbRegs.ADCINLTRIM2-3
AdccRegs.ADCINLTRIM2-3
Internal oscillator AnalogSubsysRegs.INTOSC1TRIM Degraded frequency accuracy and
temperature drift of the internal oscillators.
AnalogSubsysRegs.INTOSC2TRIM
Buffered DAC
offset DacaRegs.DACTRIM Degraded offset error specification of the
buffered DAC. No workaround available.
DacbRegs.DACTRIM
Silicon Revision A Usage Notes and Advisories www.ti.com
36 TMS320F28004x Real-Time MCUs Silicon Errata
Silicon Revisions B, A, 0 SPRZ439G – JANUARY 2017 – REVISED AUGUST 2022
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