Texas Instruments Silicon Errata TMS320F28379S User manual

TMS320F28379S, TMS320F28377S,
TMS320F28376S, TMS320F28375S,
TMS320F28374S Delfino Microcontrollers
Silicon Errata
Literature Number: SPRZ422D
August 2014–Revised July 2016

2SPRZ422D–August 2014–Revised July 2016
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Table of Contents
Contents
1 Introduction......................................................................................................................... 4
2 Device and Development Support Tool Nomenclature.............................................................. 4
3 Device Markings .................................................................................................................. 5
4 Usage Notes and Known Design Exceptions to Functional Specifications.................................. 6
4.1 Usage Notes.............................................................................................................. 6
4.1.1 PIE: Spurious Nested Interrupt After Back-to-Back PIEACK Write and Manual CPU Interrupt Mask
Clear............................................................................................................ 6
4.2 Known Design Exceptions to Functional Specifications ............................................................ 7
5 Documentation Support ...................................................................................................... 23
Revision History.......................................................................................................................... 24

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List of Figures
List of Figures
1 Example of Device Markings............................................................................................... 5
2 Example of Device Nomenclature......................................................................................... 5
3 Single-Ended Input Model................................................................................................. 11
List of Tables
1 Determining Silicon Revision From Lot Trace Code ................................................................... 5
2 List of Usage Notes.......................................................................................................... 6
3 Table of Contents for Advisories........................................................................................... 7
4 List of Advisories............................................................................................................. 8
5 Memories Impacted by Advisory ......................................................................................... 20

4SPRZ422D–August 2014–Revised July 2016
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TMS320F2837xS Delfino™ Microcontrollers
Silicon Errata
SPRZ422D–August 2014–Revised July 2016
TMS320F2837xS Delfino™ Microcontrollers
Delfino, PowerPAD, TMS320, controlSUITE are trademarks of Texas Instruments.
All other trademarks are the property of their respective owners.
1 Introduction
This document describes the silicon updates to the functional specifications for the TMS320F2837xS
microcontrollers (MCUs).
The updates are applicable to the following:
• 337-ball New Fine Pitch Ball Grid Array, ZWT Suffix
• 176-pin PowerPAD™ Thermally Enhanced Low-Profile Quad Flatpack, PTP Suffix
• 100-Pin PowerPAD Thermally Enhanced Thin Quad Flatpack, PZP Suffix
2 Device and Development Support Tool Nomenclature
To designate the stages in the product development cycle, TI assigns prefixes to the part numbers of all
[TMS320] DSP devices and support tools. Each TMS320™ DSP commercial family member has one of
three prefixes: TMX, TMP, or TMS (for example, TMS320F28379S). Texas Instruments recommends two
of three possible prefix designators for its support tools: TMDX and TMDS. These prefixes represent
evolutionary stages of product development from engineering prototypes (with TMX for devices and TMDX
for tools) through fully qualified production devices and tools (with TMS for devices and TMDS for tools).
TMX Experimental device that is not necessarily representative of the final device's electrical
specifications
TMP Final silicon die that conforms to the device's electrical specifications but has not
completed quality and reliability verification
TMS Fully qualified production device
Support tool development evolutionary flow:
TMDX Development-support product that has not yet completed Texas Instruments internal
qualification testing
TMDS Fully qualified development-support product
TMX and TMP devices and TMDX development-support tools are shipped against the following
disclaimer:
"Developmental product is intended for internal evaluation purposes."
TMS devices and TMDS development-support tools have been characterized fully, and the quality and
reliability of the device have been demonstrated fully. TI's standard warranty applies.
Predictions show that prototype devices (TMX or TMP) have a greater failure rate than the standard
production devices. Texas Instruments recommends that these devices not be used in any production
system because their expected end-use failure rate still is undefined. Only qualified production devices are
to be used.
TI device nomenclature also includes a suffix with the device family name. This suffix indicates the
package type (for example, PTP) and temperature range (for example, T).

PREFIX
TMS
TMX = experimental device
TMP = prototype device
TMS = qualified device
320
DEVICE FAMILY
320 = TMS320 MCU Family
F
TECHNOLOGY
F = Flash
28379S
DEVICE
28379S
28377S
28376S
28375S
28374S
PTP
PACKAGE TYPE
176
337-Ball ZWT New Fine Pitch Ball Grid Array (nFBGA)
-Pin PTP PowerPAD Thermally Enhanced Low-Profile Quad Flatpack (HLQFP)
100-Pin PZP PowerPAD Thermally Enhanced Thin Quad Flatpack (HTQFP)
TEMPERATURE RANGE
T
−40°C to 105°C (T )
−40°C to 125°C (T )
−40°C to 125°C (T )
(Q refers to Q100 qualification for automotive applications.)
J
J
A
T
S
Q
=
=
=
YMLLLLS
YM
LLLL
S
$$
#
G4
Lot Trace Code
2-Digit Year/Month Code
Assembly Lot
Assembly Site Code
Wafer Fab Code as applicable
Silicon Revision Code
Green (Low Halogen and RoHS-compliant)
=
=
=
=
=
=
=
$$#-YMLLLLS
G4
F28379SPTPT
TMS320
Package
Pin 1
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3 Device Markings
Figure 1 provides an example of the 2837xS device markings and defines each of the markings. The
device revision can be determined by the symbols marked on the top of the package as shown in
Figure 1. Some prototype devices may have markings different from those illustrated. Figure 2 shows an
example of the device nomenclature.
Figure 1. Example of Device Markings
(1) Silicon Revision ID
Table 1. Determining Silicon Revision From Lot Trace Code
SILICON REVISION CODE SILICON REVISION REVID(1)
Address: 0x5D00C COMMENTS
B B 0x0002 This silicon revision is available as TMX.
C C 0x0003 This silicon revision is available as TMS.
Figure 2. Example of Device Nomenclature

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4 Usage Notes and Known Design Exceptions to Functional Specifications
4.1 Usage Notes
Usage notes highlight and describe particular situations where the device's behavior may not match
presumed or documented behavior. This may include behaviors that affect device performance or
functional correctness. These usage notes will be incorporated into future documentation updates for the
device (such as the device-specific data sheet), and the behaviors they describe will not be altered in
future silicon revisions.
Table 2 shows which silicon revision(s) are affected by each usage note.
Table 2. List of Usage Notes
TITLE SILICON REVISION(S)
AFFECTED
B C
PIE: Spurious Nested Interrupt After Back-to-Back PIEACK Write and Manual CPU Interrupt Mask Clear Yes Yes
4.1.1 PIE: Spurious Nested Interrupt After Back-to-Back PIEACK Write and Manual CPU Interrupt
Mask Clear
Revision(s) Affected: B, C
Certain code sequences used for nested interrupts allow the CPU and PIE to enter an inconsistent state
that can trigger an unwanted interrupt. The conditions required to enter this state are:
1. A PIEACK clear is followed immediately by a global interrupt enable (EINT or asm(" CLRC INTM")).
2. A nested interrupt clears one or more PIEIER bits for its group.
Whether the unwanted interrupt is triggered depends on the configuration and timing of the other
interrupts in the system. This is expected to be a rare or nonexistent event in most applications. If it
happens, the unwanted interrupt will be the first one in the nested interrupt's PIE group, and will be
triggered after the nested interrupt re-enables CPU interrupts (EINT or asm(" CLRC INTM")).
Workaround: Add a NOP between the PIEACK write and the CPU interrupt enable. Example code is
shown below.
//Bad interrupt nesting code
PieCtrlRegs.PIEACK.all = 0xFFFF; //Enable nesting in the PIE
EINT; //Enable nesting in the CPU
//Good interrupt nesting code
PieCtrlRegs.PIEACK.all = 0xFFFF; //Enable nesting in the PIE
asm(" NOP"); //Wait for PIEACK to exit the pipeline
EINT; //Enable nesting in the CPU

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4.2 Known Design Exceptions to Functional Specifications
Table 3. Table of Contents for Advisories
Title ...................................................................................................................................... Page
Advisory —Analog Trim of Some TMX Devices ..................................................................................... 9
Advisory —ADC: ADC Post-Processing Block Limit Compare................................................................... 10
Advisory —ADC: ADC Offset Trim in Different Modes ............................................................................ 10
Advisory —ADC: Random Conversion Errors...................................................................................... 10
Advisory —ADC: ADC PPB Event Trigger (ADCxEVT) to ePWM Digital Compare Submodule ............................ 11
Advisory —ADC: 12-Bit Switch Resistance ........................................................................................ 11
Advisory —ADC: 12-Bit Input Capacitance When Switching Channel Groups ................................................ 11
Advisory —XRS may Toggle During Power Up .................................................................................... 12
Advisory —USB: USB DMA Event Triggers are not Supported.................................................................. 12
Advisory —VREG: VREG Will be Enabled During Power Up Irrespective of VREGENZ .................................... 12
Advisory —Flash: A Single-Bit ECC Error May Cause Endless Calls to Single-Bit-Error ISR ............................... 12
Advisory —ePIE: Spurious VCU Interrupt (ePIE 12.6) Can Occur When First Enabled...................................... 13
Advisory —eQEP: Position Counter Incorrectly Reset on Direction Change During Index .................................. 13
Advisory —PLL: May Not Lock on the First Lock Attempt........................................................................ 14
Advisory —SDFM: Data Filter Output Does Not Saturate at Maximum Value With Sinc3 and OSR = 256................ 15
Advisory —SDFM: Spurious Data Acknowledge Event When Data Filter is Configured and Enabled for the First Time 15
Advisory —SDFM: Spurious Data Acknowledge Event When Data Filter is Synchronized Using PWM FILRES Signal 15
Advisory —SDFM: Comparator Filter Module may Generate Spurious Over-Value and Under-Value Conditions ....... 16
Advisory —SDFM: Dynamically Changing Threshold Settings (LLT, HLT), Filter Type, or COSR Settings Will Trigger
Spurious Comparator Events................................................................................................. 16
Advisory —SDFM: Dynamically Changing Data Filter Settings (Such as Filter Type or DOSR) Will Trigger Spurious
Data Acknowledge Events.................................................................................................... 16
Advisory —FPU: FPU-to-CPU Register Move Operation Preceded by Any FPU 2p Operation............................. 17
Advisory —FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions ............................... 18
Advisory —Memory: Prefetching Beyond Valid Memory ......................................................................... 20
Advisory —CMPSS: COMPxLATCH May Not Clear Properly Under Certain Conditions .................................... 21
Advisory —CMPSS: Ramp Generator May Not Start Under Certain Conditions .............................................. 21
Advisory —Boot ROM: Device Will Hang During Boot if X1 Clock Source is not Present ................................... 22

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Table 4 shows which silicon revision(s) are affected by each advisory.
Table 4. List of Advisories
TITLE SILICON REVISION(S)
AFFECTED
B C
Analog Trim of Some TMX Devices Yes
ADC: ADC Post-Processing Block Limit Compare Yes Yes
ADC: ADC Offset Trim in Different Modes Yes Yes
ADC: Random Conversion Errors Yes
ADC: ADC PPB Event Trigger (ADCxEVT) to ePWM Digital Compare Submodule Yes
ADC: 12-Bit Switch Resistance Yes
ADC: 12-Bit Input Capacitance When Switching Channel Groups Yes
XRS may Toggle During Power Up Yes
USB: USB DMA Event Triggers are not Supported Yes Yes
VREG: VREG Will be Enabled During Power Up Irrespective of VREGENZ Yes
Flash: A Single-Bit ECC Error May Cause Endless Calls to Single-Bit-Error ISR Yes Yes
ePIE: Spurious VCU Interrupt (ePIE 12.6) Can Occur When First Enabled Yes
eQEP: Position Counter Incorrectly Reset on Direction Change During Index Yes Yes
PLL: May Not Lock On the First Lock Attempt Yes Yes
SDFM: Data Filter Output Does Not Saturate at Maximum Value With Sinc3 and OSR = 256 Yes Yes
SDFM: Spurious Data Acknowledge Event When Data Filter is Configured and Enabled for the First
Time Yes Yes
SDFM: Spurious Data Acknowledge Event When Data Filter is Synchronized Using PWM FILRES
Signal Yes Yes
SDFM: Comparator Filter Module may Generate Spurious Over-Value and Under-Value Conditions Yes Yes
SDFM: Dynamically Changing Threshold Settings (LLT, HLT), Filter Type, or COSR Settings Will
Trigger Spurious Comparator Events Yes Yes
SDFM: Dynamically Changing Data Filter Settings (Such as Filter Type or DOSR) Will Trigger
Spurious Data Acknowledge Events Yes Yes
FPU: FPU-to-CPU Register Move Operation Preceded by Any FPU 2p Operation Yes Yes
FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions Yes Yes
Memory: Prefetching Beyond Valid Memory Yes Yes
CMPSS: COMPxLATCH May Not Clear Properly Under Certain Conditions Yes Yes
CMPSS: Ramp Generator May Not Start Under Certain Conditions Yes Yes
Boot ROM: Device Will Hang During Boot if X1 Clock Source is not Present Yes

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Advisory Analog Trim of Some TMX Devices
Revision(s) Affected B
Details Some TMX samples may not have analog trims programmed. This could degrade the
performance of the ADC, buffered DAC, and internal oscillators. A value of all zeros in
these trim registers will have the following impact.
TRIM REGISTER IMPACT OF TRIM VALUE EQUAL TO ZERO
ADC reference AnalogSubsysRegs.ANAREFTRIMA Degraded performance of the ADC for all
specifications.
AnalogSubsysRegs.ANAREFTRIMB
AnalogSubsysRegs.ANAREFTRIMC
AnalogSubsysRegs.ANAREFTRIMD
ADC linearity AdcaRegs.ADCINLTRIM1-6 Degraded INL and DNL specifications of the ADC
in 16-bit mode. No workaround available.
AdcbRegs.ADCINLTRIM1-6
AdccRegs.ADCINLTRIM1-6
AdcdRegs.ADCINLTRIM1-6
ADC offset AdcaRegs.ADCOFFTRIM Degraded performance of the ADC offset error
specification.
AdcbRegs.ADCOFFTRIM
AdccRegs.ADCOFFTRIM
AdcdRegs.ADCOFFTRIM
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
DaccRegs.DACTRIM
Workaround(s) The following workarounds can be used for improved performance, though it still may not
meet data sheet specifications.
If the ADC reference trim registers contain all zeros, write the static reference trim value
of 0x7BDD to the reference trim register for all ADCs.
Missing ADC offset trim can be generated by following the instructions in the “ADC
Zero Offset Calibration” section of the TMS320F2837xS Delfino Microcontrollers
Technical Reference Manual.
If the internal oscillator trim contains all zeros, the user can adjust the lowest 10 bits of
the oscillator trim register between 1 (minimum) and 1023 (maximum) while observing
the system clock on the XCLOCKOUT pin.

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Advisory ADC: ADC Post-Processing Block Limit Compare
Revision(s) Affected B, C
Details When using a non-zero offset reference in the ADC post-processing block (PPB), the
resultant ADCPPBxRESULT can be signed. TRIPHI or TRIPLO limit compares do not
function correctly with this result if it is signed.
Workaround(s) When using the TRIPHI or TRIPLO limit compares, leave the offset reference as zero.
The offset reference (and zero compare) can be used as long as the limit compares are
disabled.
If the limit compares, the offset reference, and the zero-crossing compare are to be used
at the same time, then two PPBs can be used. Both PPBs should be configured to use
the same SOC. One PPB can implement the TRIPHI and/or TRIPLO limit compares
while the other can implement offset reference subtraction and zero-crossing detection.
Advisory ADC: ADC Offset Trim in Different Modes
Revision(s) Affected B, C
Details A different offset trim is required when switching between 12-bit and 16-bit resolution
and when switching between single-ended and differential signaling mode.
Workaround(s) Whenever setting the resolution or signal mode of the ADC, use the “AdcSetMode”
function in controlSUITE™. This will ensure the correct trims are loaded into the offset
trim register. Note that on start-up, trims will be loaded for 12-bit, single-ended operation.
Advisory ADC: Random Conversion Errors
Revision(s) Affected B
Details The ADC may have errors at a rate as high as 1 in 106.5 ADC conversions in 12-bit mode
and as high as 1 in 108.75 conversions in 16-bit mode. When a conversion error occurs, it
will be a significant random jump in the digital output of the ADC without a corresponding
change in the ADC input voltage, otherwise known as a “sparkle code”. The magnitude
of this jump will typically be in the range of 20 LSBs to 200 LSBs; however, larger or
smaller jumps may occur.
Workaround(s) For the revisions affected, the error rate will be lower than 1 error in 1014.5 ADC
conversions for both 12-bit mode and 16-bit mode when all of the following
configurations are used:
• The S+H duration is at least 320 ns
• ADCCLK is 40 MHz or less
• ADCCLK prescale is a whole number: /1.0, /2.0, /3.0, /4.0, /5.0, /6.0, /7.0, or /8.0
• The value of 0x7000 is written to memory locations 0x0000 743F, 0x0000 74BF,
0x0000 753F, and 0x0000 75BF (writing this value is only valid when the ADCCLK
prescale is a whole number).

AC
ADCINx
ADC
11.5 pF
Switch
Rs
Ron
CpCh
VREFLO
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Advisory ADC: ADC PPB Event Trigger (ADCxEVT) to ePWM Digital Compare Submodule
Revision(s) Affected B
Details The ADCxEVT trigger to the ePWM digital compare submodule may not be detected by
the ePWM.
Workaround(s) The ADCxEVT can generate an ADCx_EVT interrupt to the PIE. The ISR can be used to
perform the desired task in software.
Advisory ADC: 12-Bit Switch Resistance
Revision(s) Affected B
Details The ADC input model should be used to select the sample-and-hold (S+H) duration for
each ADC input. For the revisions affected, the 12-bit input model under-estimates the
value of the sampling switch resistance (Ron). A Ron value of 2 kΩshould be used to
select the S+H duration for these revisions.
Workaround(s) For the revisions affected, the S+H duration should be chosen to account for the
additional switch resistance.
Advisory ADC: 12-Bit Input Capacitance When Switching Channel Groups
Revision(s) Affected B
Details The ADC input model should be used to select the sample-and-hold (S+H) duration for
each ADC input. For the revisions affected, if the currently converting channel is an
even-numbered channel and the previously converted channel was an odd-numbered
channel (or vice versa), then the 12-bit input model will not accurately predict ADC input
performance. Under these conditions, an additional capacitance should be added to the
model. This capacitance has a value of 11.5 pF and should be placed between the S+H
switch and Ron as shown in Figure 3.
Figure 3. Single-Ended Input Model
Workaround(s) For the revisions affected, when subsequent conversions switch between channel
groups, the S+H duration should be chosen to account for the additional capacitance.

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Advisory XRS may Toggle During Power Up
Revision(s) Affected B
Details During device power up, the XRS pin may toggle high prematurely. After the VDDIO and
VDD supplies reach the recommended operation conditions, the XRS pin behavior will be
per the pin description. This is only an issue with the external state of the XRS pin.
Internally, the device will be held in reset by the POR logic until the supplies are within
an acceptable range and XRS is high.
Workaround(s) Disregard XRS activity on the board prior to supplies reaching recommended operating
conditions.
Advisory USB: USB DMA Event Triggers are not Supported
Revision(s) Affected B, C
Details The USB module generates inadvertent extra DMA requests, causing the FIFO to
overflow (on IN endpoints) or underflow (on OUT endpoints). This causes invalid IN
DATA packets (larger than the maximum packet size) and duplicate receive data.
Workaround(s) None
Advisory VREG: VREG Will be Enabled During Power Up Irrespective of VREGENZ
Revision(s) Affected B
Details During power up of the 3.3-V VDDIO, the internal Voltage Regulator (VREG) will be active
until the 1.2-V VDD supply reaches approximately 0.7 V. After this time, the VREGENZ
pin tied to VDDIO will disable the internal VREG. This will not impact device operation.
Workaround(s) None
Advisory Flash: A Single-Bit ECC Error May Cause Endless Calls to Single-Bit-Error ISR
Revision(s) Affected B, C
Details When a single-bit ECC error is detected, the CPU executes the single-bit-error interrupt
service routine (ISR). When the ISR returns, the same instruction that caused the first
error is fetched again. If the ECC error threshold (ERR_THRESHOLD.THRESHOLD)
is 0, then the same error is detected and another ISR is executed. This continues in an
endless loop. This sequence of events only occurs if the error is caused by a program
fetch operation, not a data read.
Workaround(s) Set the error threshold bit-field (ERR_THRESHOLD.THRESHOLD) to a value greater
than or equal to 1. Note that the default value of the threshold bit-field is 0.

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Advisory ePIE: Spurious VCU Interrupt (ePIE 12.6) Can Occur When First Enabled
Revision(s) Affected B
Details The VCU-II can power up in a state which incorrectly sets the VCU VSTATUS[DIVE]
error bit and, subsequently PIEIFR12[INTx6], when the CPU is released from reset.
When the VCU interrupt enable PIEIER12[INTx6] is enabled for the first time by the
application, a spurious interrupt can occur due to the erroneous pending interrupt.
Workaround(s) Before enabling VCU interrupt 12.6, execute the following instructions to avoid the
spurious interrupt.
// Clear VCU divide by zero status
asm(" VCLRDIVE");
// Clear PIE interrupt for VCU
PieCtrlRegs.PIEIFR12.bit.INTx6 = 0;
Beginning with revision C silicon, the Boot ROM will perform the above workaround
before branching to the application.
Advisory eQEP: Position Counter Incorrectly Reset on Direction Change During Index
Revision(s) Affected B, C
Details While using the PCRM = 0 configuration, if the direction change occurs when the index
input is active, the position counter (QPOSCNT) could be reset erroneously, resulting in
an unexpected change in the counter value. This could result in a change of up to
±4 counts from the expected value of the position counter and lead to unexpected
subsequent setting of the error flags.
While using the PCRM = 0 configuration [that is, Position Counter Reset on Index Event
(QEPCTL[PCRM] = 00)], if the index event occurs during the forward movement, then
the position counter is reset to 0 on the next eQEP clock. If the index event occurs
during the reverse movement, then the position counter is reset to the value in the
QPOSMAX register on the next eQEP clock. The eQEP peripheral records the
occurrence of the first index marker (QEPSTS[FIMF]) and direction on the first index
event marker (QEPSTS[FIDF]) in QEPSTS registers. It also remembers the quadrature
edge on the first index marker so that same relative quadrature transition is used for
index event reset operation.
If the direction change occurs while the index pulse is active, the module would still
continue to look for the relative quadrature transition for performing the position counter
reset. This results in an unexpected change in the position counter value.
The next index event without a simultaneous direction change will reset the counter
properly and work as expected.
Workaround(s) Do not use the PCRM = 0 configuration if the direction change could occur while the
index is active and the resultant change of the position counter value could affect the
application.
Other options for performing position counter reset, if appropriate for the application
[such as Index Event Initialization (IEI)], do not have this issue.

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Advisory PLL: May Not Lock on the First Lock Attempt
Revision(s) Affected B, C
Details On a very small number of devices, the PLL may not start properly at device power up or
wake up from Hibernate. The PLLSTS[LOCKS] bit is set, but the PLL does not produce
a clock.
Once the PLL has properly started, the PLL can be disabled and re-enabled with no
issues and will stay locked. However, the PLL lock problem could re-occur on a
subsequent power-up or Hibernate cycle.
If the SYSPLL has not properly started and is selected as the CPU clock source, the
CPU will stop executing instructions.
This advisory applies to both PLLs, with a different workaround for each.
Workaround(s) SYSPLL Workaround:
Repeated lock attempts will reduce the likelihood of seeing the condition on the final
attempt. TI recommends a minimum of five lock sequences in succession when the PLL
is configured the first time after a power up. A lock sequence means disabling the PLL,
starting the PLL locking, and waiting for the LOCKS bit to set. After the final sequence,
the clock source is switched to use the PLL output as normal.
The Watchdog timer can be used to detect that the condition has occurred because it is
not clocked by the PLL output. The Watchdog should be enabled before selecting the
PLL as the clock source and configured to reset the device. If the PLL is not producing a
clock, the Watchdog will reset the device and the user initialization software will therefore
repeat the PLL initialization.
Many applications do not have a different initialization sequence for a Watchdog-initiated
reset; for these applications, no further action is required. For applications that do use a
different device initialization sequence when a Watchdog reset is detected, a flag can be
used to identify the Watchdog reset as a PLL cause. The SYSDBGCTL[BIT_0] bit (which
is bit 0 at 0x0005D12C) can be set active during the PLL lock sequence and used to
distinguish a Watchdog PLL retry attempt versus a different Watchdog reset source.
See the ControlSUITE InitSysPll() function for an example implementation of this
workaround.
AUXPLL Workaround:
CPU Timer 2 can be used to detect that the AUXPLL is active before it is used as a
clock source for USB. If the AUXPLL is not active, repeat the lock attempt in the same
manner as the SYSPLL workaround.
See the ControlSUITE InitAuxPll() function for an example implementation of this
workaround.
NOTE: The USB Boot Mode does not implement the previous workarounds.
Applications using USB Boot will need to implement any retry attempts at
the system level.

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Advisory SDFM: Data Filter Output Does Not Saturate at Maximum Value With Sinc3 and
OSR = 256
Revision(s) Affected B, C
Details If the differential input of the Sigma-Delta Filter Module (SDFM) is greater than or equal
to +FSR (full-scale differential voltage input range), then the output of the SDFM clips
with a stream of ones. When this stream of ones is fed to a data filter that is configured
as a sinc3 filter with an OSR = 256, the output of the filter does not saturate at the
maximum value (16777215 in 32-bit mode or 32767 in 16-bit mode); but, instead roll
over to the minimum value (–16777216 in 32-bit mode or –32768 in 16-bit mode).
Workaround(s) Maintain the differential input of the SDFM in the specified linear input range as specified
in the modulator data sheet.
Advisory SDFM: Spurious Data Acknowledge Event When Data Filter is Configured and
Enabled for the First Time
Revision(s) Affected B, C
Details When the SDFM data filter is configured and enabled for the first time, it is possible to
get one spurious data acknowledge event (AFx) before the data filter settles to give
correct digital data. Subsequent data acknowledge events (AFx)/DMA events occur
correctly as per data filter configuration.
Workaround(s) Do the following:
1. Configure and enable the SDFM data filter.
2. Delay for at least latency of data filter + 5 SD-Cx clock cycles.
3. Enable SDFM data acknowledge interrupts/DMA events.
Advisory SDFM: Spurious Data Acknowledge Event When Data Filter is Synchronized Using
PWM FILRES Signal
Revision(s) Affected B, C
Details When the SDFM data filters are synchronized using the PWM FILRES signal, it is
possible to get a spurious data acknowledge event (AFx) before the data filter settles to
give correct digital data. Subsequent data acknowledge events (AFx) occur correctly as
per data filter configuration before the next PWM FILRES signal.
Workaround(s) Do the following:
1. Choose any PWMx to work in the same time base as the PWM that generates the
FILRES pulse.
2. PWMx should also interrupt the CPU/CLA at least 1.2 µs after the PWM FILRES
pulse gets applied in order to clear the SDIFLG register that may be set because of
the spurious data acknowledge event.
3. SDFM_CPUISR or SDFM_CLATask:
(a) Collect the required number of samples, N, after the FILRES pulse.
(b) If the number of samples is less than or equal to N, clear the SDIFLG register;
otherwise, do not clear the SDIFLG register to prevent further SDFM interrupts.

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Advisory SDFM: Comparator Filter Module may Generate Spurious Over-Value and Under-
Value Conditions
Revision(s) Affected B, C
Details When interrupts are enabled in the SDFM comparator module, it may trigger spurious
over-value (SDIFLG.IEHx, x = 1 to 4) or under-value (SDIFLG.IELx, x = 1 to 4)
conditions. These are depicted as IELx and IEHx interrupt outputs in the “Block Diagram
of One Filter Module” figure in the TMS320F2837xS Delfino Microcontrollers Technical
Reference Manual.
Workaround(s) These erroneous interrupts can be eliminated by implementing the following workaround:
• Comparator OSR (COSR) value should be greater than or equal to 5.
• After changing COSR, wait for at least latency of comparator filter and 5 SD-Cx
cycles before enabling comparator interrupts SDCPARMx.IEH and SDCPARMx.IEL.
Advisory SDFM: Dynamically Changing Threshold Settings (LLT, HLT), Filter Type, or COSR
Settings Will Trigger Spurious Comparator Events
Revision(s) Affected B, C
Details When SDFM comparator settings—such as filter type, lower/upper threshold, or COSR
settings—are changed while low-level/high-level events are enabled, a spurious
comparator lower threshold (or) higher threshold event will be triggered.
Workaround(s) When comparator settings need to be changed dynamically, follow the procedure below:
1. Disable the SDFM comparator interrupts.
2. Change comparator settings such as lower/upper threshold, filter type, or COSR.
3. Comparator OSR (COSR) value should be greater than or equal to 5.
4. Delay for at least a latency of comparator filter + 5 SD-Cx clock cycles.
5. Enable the SDFM comparator interrupts.
Advisory SDFM: Dynamically Changing Data Filter Settings (Such as Filter Type or DOSR)
Will Trigger Spurious Data Acknowledge Events
Revision(s) Affected B, C
Details When SDFM data filter settings—such as filter type or DOSR settings—are changed
while the data filter and its data acknowledge events are enabled, spurious data
acknowledge events will be triggered.
Workaround(s) When data filter settings need to be changed dynamically, follow the procedure below:
1. Disable the SDFM data filter.
2. Change data filter settings such as filter type or DOSR.
3. Delay for at least a latency of data filter + 5 SD-Cx clock cycles.
4. Enable the SDFM data filter.

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Advisory FPU: FPU-to-CPU Register Move Operation Preceded by Any FPU 2p Operation
Revision(s) Affected B, C
Details This advisory applies when a multi-cycle (2p) FPU instruction is followed by a FPU-to-
CPU register transfer. If the FPU-to-CPU read instruction source register is the same as
the 2p instruction destination, then the read may be of the value of the FPU register
before the 2p instruction completes. This occurs because the 2p instructions rely on
data-forwarding of the result during the E2 phase of the pipeline. If a pipeline stall
happens to occur in the E3 phase, the result does not get forwarded in time for the read
instruction.
The 2p instructions impacted by this advisory are MPYF32, ADDF32, SUBF32, and
MACF32. The destination of the FPU register read must be a CPU register (ACC, P, XT,
XAR0…XAR7). This advisory does not apply if the register read is a FPU-to-FPU
register transfer.
In the example below, the 2p instruction, MPYF32, uses R6H as its destination. The
FPU register read, MOV32, uses the same register, R6H, as its source, and a CPU
register as the destination. If a stall occurs in the E3 pipeline phase, then MOV32 will
read the value of R6H before the MPYF32 instruction completes.
Example of Problem:
MPYF32 R6H, R5H, R0H ; 2p FPU instruction that writes to R6H
|| MOV32 *XAR7++, R4H
F32TOUI16R R3H, R4H ; delay slot
ADDF32 R2H, R2H, R0H
|| MOV32 *--SP, R2H ; alignment cycle
MOV32 @XAR3, R6H ; FPU register read of R6H
Workaround(s) Treat MPYF32, ADDF32, SUBF32, and MACF32 in this scenario as 3p-cycle
instructions. Three NOPs or non-conflicting instructions must be placed in the delay slot
of the instruction.
The C28x code generation tools v.6.2.0 and later will both generate the correct
instruction sequence and detect the error in assembly code. In previous versions, v6.0.5
(for the 6.0.x branch) and v.6.1.2 (for the 6.1.x branch), the compiler will generate the
correct instruction sequence but the assembler will not detect the error in assembly
code.
Example of Workaround:
MPYF32 R6H, R5H, R0H
|| MOV32 *XAR7++, R4H ; 3p FPU instruction that writes to R6H
F32TOUI16R R3H, R4H ; delay slot
ADDF32 R2H, R2H, R0H
|| MOV32 *--SP, R2H ; delay slot
NOP ; alignment cycle
MOV32 @XAR3, R6H ; FPU register read of R6H

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Advisory FPU: LUF, LVF Flags are Invalid for the EINVF32 and EISQRTF32 Instructions
Revision(s) Affected B, C
Details This advisory applies to the EINVF32 and EISQRTF32 instructions. The expected results
for these instructions are correct; however, the underflow (LUF) and overflow (LVF) flags
are not. These flags are invalid and should not be used.
Workaround(s) Do not rely on the LUF and LVF flags to catch underflow/overflow conditions resulting
from the EINVF32 and EISQRTF32 instructions. Instead, check the operands for the
following conditions (in code) before using each instruction:
EINVF32 Divide by 0
EISQRTF32 Divide by 0, Divide by a negative input
Disregard the contents of the LUF and LVF flags by saving the flags to the stack before
calling the instruction, and subsequently restoring the values of the flags once the
instruction completes.
MOV32 *SP++,STF ; Save off current status flags
EISQRTF32/EINVF32 ; Execute operation
NOP ; Wait for operations to complete
MOV32 STF,*--SP ; Restore previous status flags
If the PIE interrupts are tied to the LUF and LVF flags, disable the interrupts (at the PIE)
before using either the EINVF32 or EISQRTF32 instruction. Check to see if the LUF and
LVF flags are set; if they are, a variable can be set to indicate that a false LUF/LVF
condition is detected. Clear the flags in the STF (FPU status flag) before re-enabling the
interrupts.
Once the interrupts are re-enabled at the PIE, the interrupt may occur (if the LUF/LVF
interrupt lines were asserted by either of the two instructions) and execution branches to
the Interrupt Service Routine (ISR). Check the flag to determine if a false condition has
occurred; if it has, disregard the interrupt.
Do not clear the PIE IFR bits (that latch the LUF and LVF flags) directly because an
interrupt event on the same PIE group (PIE group 12) may inadvertently be missed.
Here is an example:
_flag_LVFLUF_set .usect ".ebss",2,1,1
...
MOV32 *SP++,STF ; Save off current status flags
; Load the PieCtrlRegs page to the DP
MOVW DP, #_PieCtrlRegs.PIEIER12.all
; Zero out PIEIER12.7/8, i.e. disable LUF/LVF interrupts
AND @_PieCtrlRegs.PIEIER12.all, #0xFF3F
EISQRTF32/EINVF32 ; Execute operation
MOVL XAR3, #_flag_LVFLUF_set ; Wait for operation to complete
MOV32 *+XAR3[0], STF ; save STF to _flag_LVFLUF_set
AND *+XAR3[0], #0x3 ; mask everything but LUF/LVF
; Clear Latched overflow, underflow flag
SETFLG LUF=0, LVF=0
; Re-enable PIEIER12.7/8, i.e. re-enable the LUF/LVF interrupts
OR @_PieCtrlRegs.PIEIER12.all, #0x00C0
MOV32 STF,*--SP ; Restore previous status flags

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In the ISR,
__interrupt void fpu32_luf_lvf_isr (void)
{// Check the flag for whether the LUF, LVF flags set by
// either EISRTF32 or EINVF32
if((flag_LVFLUF_set & 0x3U) != 0U)
{//Reset flag
flag_LVFLUF_set = 0U;
// Do Nothing
}
else
{//If flag_LVFLUF_set was not set then this interrupt
// is the legitimate result of an overflow/underflow
// from an FPU operation (not EISQRTF32/EINVF32)
...
// Handle Overflow/Underflow condition
...
...
...
}
// Ack the interrupt and exit
}

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Advisory Memory: Prefetching Beyond Valid Memory
Revision(s) Affected B, C
Details The C28x CPU prefetches instructions beyond those currently active in its pipeline. If the
prefetch occurs past the end of valid memory, then the CPU may receive an invalid
opcode.
Workaround The prefetch queue is 8 x16 words in depth. Therefore, code should not come within
8 words of the end of valid memory. Prefetching across the boundary between two valid
memory blocks is all right.
Example 1: M1 ends at address 0x7FF and is not followed by another memory block.
Code in M1 should be stored no farther than address 0x7F7. Addresses 0x7F8-0x7FF
should not be used for code.
Example 2: M0 ends at address 0x3FF and valid memory (M1) follows it. Code in M0
can be stored up to and including address 0x3FF. Code can also cross into M1 up to
and including address 0x7F7.
Table 5. Memories Impacted by Advisory
MEMORY TYPE ADDRESSES IMPACTED F28377S
F28375S F28376S F28374S
M1 0x0000 07F8–0x0000 07FF Yes Yes
GS11 0x0001 7FF8–0x0001 7FFF No Yes
GS15 0x0001 BFF8–0x0001 BFFF Yes N/A
Flash 0x000B FFF8–0x000B FFFF No Yes