The errata concerns the DBG-CPU interface in DBG mode whilst configured

for tagging. If an interrupt occurs at the moment that a tag is attached

to an opcode being loaded into the instruction queue, the flag will get

set, but the part may not enter active BDM mode. 



Using the DBG configuration BDM=DBGBRK=1, BEGIN=0, an event causing a

flag to be set should cause a break to BDM. The flag gets set, but the

part does not enter active BDM mode. The CPU executes the interrupt

service routine, instead, and returns to the correct position in the

program flow, but the breakpoint to BDM is missed.



The problem does not occur if the DBG module is configured for operation

in BKP mode (BKABEN=1). This is because, even if the flag bit is set,

the BKABEN bit is not cleared. On returning from the interrupt service

routine, the tag is re-applied when the PC is fetched after the

interrupt service routine, and the part enters BDM after the interrupt

service routine. In BKP mode with TRGSEL=0, no flags are set when a

taghit occurs. 



In BKP mode with TRGSEL=1, the flag is also set erroneously on entering

the interrupt service routine. However, it is unlikely that a user would

be affected by the flag being set early (unless the service routine were

exceptionally long), due to the length of time needed to read out the

DBGSR (flag bits) over the BKGD pin; typically, during this time, the

part would enter active BDM when the tag is re-applied. 

None.

Upon leaving BDM active mode, the CPU return address is stored

temporarily for a few cycles in the BDM shift register. If a BDM command

transmission is detected during this time, the return address will be

manipulated in the BDM shift register. This situation is likely to occur

when a CPU BGND instruction is executed in user code during debugging

under the following conditions:



(i) The BDM module is not enabled AND

(ii) BDM commands are sent from the host



If this situation occurs, the CPU will execute BDM firmware and will

check the status of the ENBDM bit in the BDMSTS register. If the BDM is

disabled, the ENBDM bit will be clear, and hence the BDM firmware will

be exited and the shift register manipulation described above will occur. 

Avoid using the BGND instruction when the ENBDM bit in the BDMSTS

register is cleared. 

If the ECLK is used as an external bus control signal (ESTR=1) the first

external access is lost after switching from a single chip mode with

enabled ECLK output to an expanded mode. The ECLK is erroneously held in

the high phase thus the first external bus access does not generate a

rising ECLK edge for the external logic to latch the address. The ECLK

stretches low after the lost access resulting in all following external

accesses to be valid. 

Enter expanded mode with ECLK output disabled (NECLK=1). Enable the ECLK

after switching the mode before executing the first external access. 

With the SPI configured as a slave, clearing the SPE bit (to disable 

the SPI) together with clearing the CPHA bit while the SS pin is low 

causes the transmit shift register to be locked for the next 

transmission following the SPI being re-enabled as a slave with SS 

still being low. 



This means new transmit data is not accepted for the first 

transmission after re-enabling the SPI (indicated by SPTEF staying low 

after storing transmit data into SPIDR), but for the next following 

transmission.



 

When disabling the slave SPI, CPHA should not be cleared at the same time. 

Starting a conversion with a write to ATDxCTL5 or on an external trigger

event, and aborting immediately afterwards with a write to ATDxCTL0,

ATDCTL1, ATDxCTL2 or ATDxCTL3 can fail to stop the conversion process. 

Only write to ATDxCTL4 to abort an ongoing conversion sequence.



Use the recommended start and abort procedures from the Block Guide.

Section : Initialization/Application Information 

Subsection: Setting up and starting an A/D conversion 

Subsection: Aborting an A/D conversion 

If the range of Flash addresses to be compressed is 32K or greater, the

data at one of the addresses will be effectively ignored. The address

affected is 32K from the upper address read in the data compress

algorithm, e.g., for an address range of 32K, the first data read in the

algorithm will not affect the final signature provided by the algorithm.

 

Limit range of addresses to be compressed to less than 32K addresses.

Execute multiple data compress commands to compress larger Flash address

ranges. 

It is possible that after the device enters Stop or Pseudo-Stop mode it

may reset rather than wake up normally upon reception of the wake-up

signal. 



CONDITIONS: This event will only happen provided ALL of the following

conditions are met: 

    1) Device is powered by the on-chip voltage regulator. 

    2) Device enters stop or pseudo-stop mode by execution of STOP

instruction by the CPU (provided the S-bit in CCR is cleared) 

NOTE: The part enters stop mode either after 12 oscillator clock cycles

with the PLL disengaged or 3 PLL clock cycles and 8 oscillator clock

cycles with the PLL engaged after the STOP command is executed. 

    3) The wake-up signal is activated within a specific very short

window (typically 11ns long, not longer than 20ns). The position of the

window varies between different devices, however it never starts sooner

than 1.6µs and never ends later than 4.7µs after the stop mode entry. 



This really narrow width of the susceptible window (20ns maximum) makes

the erratum unlikely to ever show in the applications life. 



The incorrect behavior will never occur if ANY of the wake-up conditions

are met at the time when the stop mode entry is attempted (an enabled

interrupt is pending). 



EFFECT: 

If this incorrect behavior occurs, the device will Reset and indicate a

Low Voltage Reset (LVR) as the reset source. 

The device will operate normally after the reset.  

None. 



-- 



Asynchronous Low Voltage Resets are possible in any microcontroller

application (due to power supply drops) and the integrated LVR and LVI

features and dedicated LVR reset vector are provided to manage this fact

cleanly. For best practice, the application's software should be written

to recover from a Low Voltage Reset in a controlled manner. An

application software written to deal with valid Low Voltage Resets

should correctly manage erroneous LVR events. 



It can also be possible to avoid erroneous Low Voltage Resets from

synchronous wake-up events by configuring the application software to

ensure that the entry into stop occurs at such a time, in relation to

the wake-up event timer, that a wake-up event does not occur within

1.6µs to 4.7µs after Stop/Pseudo-Stop entry.  

When the ATD is started with write to ATDCTL5

and, which is very unusual and not necessary,

within a certain period again started with write

to ATDCTL5. The conversion will not start at all.

This does only happen if the two consecutive writes to ATDCTL5 occur 

within one "ATD clock period". An ATD clock period is defined by a full 

rollover of the ATD clock prescaler. That is for example PRS[4:0] = 2 -

> (2+1)*2 = within 6 bus cycles.

 

Only write once to ATDCTL5 when starting a conversion.



Use the recommended start and abort procedures from the Block Guide.

Section : Initialization/Application Information Subsection: Setting up

and starting an A/D conversion Subsection: Aborting an A/D conversion 

When writing or reading the internal BDM resources (address range $FF00

to $FFFF) via BDM hardware commands, the /XCS Chip Select signal is

erroneously driven low during the BDM access. 



The /XCS signal is also driven low for CPU accesses performed to execute

BDM firmware when the CPU is in BDM active mode (BDMACT=1). This

includes the specific read/write cycle of the BDM firmware commands

READ_NEXT and WRITE_NEXT to access the targeted address of BDM firmware.



The R/W signal remains in read state in all these cases. The data

received by the above false external read accesses are discarded by the MCU.

 

None. 

If the PWM emergency shutdown feature is enabled (PWM5ENA=1) and PWM

channel 5 is disabled (PWME5=0) another lower priority function

available on the related pin can take control over the data direction.

This does not lead to a problem if input mode is maintained. If the

alternative function switches to output mode the shutdown function may

unintentionally be triggered by the output data.



 

When using the PWM emergency shutdown feature the GPIO function on the

pin associated with PWM channel 5 should be selected as an input. 



In the case that this pin is selected as an output or where an

alternative function is enabled which could drive it as an output,

enable PWM channel 5 by setting the PWME5 bit. This prevents an

active shutdown level driven on the (output) pin from resulting in an

emergency shutdown of the enabled PWM channels.



 

The pulse width of an output compare (which resets the free running

counter when TCRE = 1) will measure one more bus clock cycle than 

expected. 



 

The specification has been updated. Please refer to revision 1.1 (06 

May 2010) or later.



In description of bitfield TCRE in register TSCR2,a note has been added:

TCRE=1 and TC7!=0, the TCNT cycle period will be TC7 x "prescaler

counter width" + "1 Bus Clock". When TCRE is set and TC7 is not equal to

0, then TCNT will cycle from 0 to TC7. When TCNT reaches TC7 value, it

will last only one bus cycle then reset to 0.











 

When the PWM is used in 16-bit (concatenation) channel and the 

emergency

shutdown feature is being used, after de-asserting PWM channel 5

(note:PWMRSTRT should be set) the PWM channels (PP0-PP4) do not show 

the

state which is set by PWMLVL bit when the 16-bit counter is non-zero. 



 

None. 

In low power modes (stop/p-stop/wait ?PSWAI=1) and during PWM PP5

de-assert and when PWM counter reaching 0, the PWM channel outputs

(PP0-PP4) cannot keep the state which is set by PWMLVL bit.  





 

None. 

Configured for Infrared Receive mode, the SCI may incorrectly set the 

RXEDGIF bit if there are consecutive '00' data bits. There are two 

cases:    



Case 1: due to re-sync of the RXD input, the received edge may be 

delayed by one bus cycle. If an edge (bit = '0') is detected near 

an SCI clock edge, the next edge (bit = '0') may be detected one 

SCI clock later than expected due to re-sync logic. 



Case 2: if external baud is slower than SCI receiver, the next edge 

may be detected later than expected.



This glitch can be detected by the RXEDGIF circuit, but it does not 

impact the final data result because the SCI receive and data recovery 

logic takes samples at RT8, RT9, and RT10.

 



 

Case 1 and case 2 may occurs at same time. To avoid those unexpected 

RXEDGIF at IR mode, the external baud should be kept a little bit 

faster than receiver baud by:

                 P > (1/16)/(SBR)

                        or

                 (P)(SBR)(16)> 1



Where SBR is baud of receiver, P is external baud faster ratio. 

For example:

1.- When SBR = 16, P = 0.4%, this means the external baud should be at 

least 0.4% faster than receiver.

2.- When SBR = 4, P = 1.6%, this means the external baud should be at 

least 1.6% faster than receiver.

 

Case 1 will cover case 2, i.e. case 1 is the worst case. If case1 is 

solved, case 2 is also solved.