When security is enabled (MCU is reset with bits[1:0] of the flash 

security byte at address $FF0F set to '00', '01' or '11'), security 

cannot be disabled using the BDM mass erase/security byte reprogram 

sequence. A bug causes the blank check (performed by the BDM secure 

firmware) to fail and as a result the flash security byte cannot be 

reprogrammed to the unsecure state. 

Do not enable security by leaving bits[1:0] of the flash security byte 

programmed to '10'. (Ensure that these bits are programmed to '10' 

BEFORE resetting the MCU otherwise security will be enabled).



OR



The security can be disabled by reprogramming bits[1:0] of the security 

byte to '10' using a software routine embedded within the user program. 

The routine could, for example, be initiated by a user specified 

command issued through the SCI interface.



 

An invalid UDMA write sequence exists under a specific condition:

1) IQUE buffer is empty

2) ATA5HC controller buffer is not full

3) ATA device issues a transfer pausing with a termination sequence

4) USB receiver has just received a packet and stored it in the IQUE

buffer

If all of the above conditions occur simultaneously, this will result in

a word being missed and the transfer hanging.  

Monitor the IQUE buffer in software and swap buffer resources out if 

~30

entries remain.

 

 

The default reset state for the read/write enable signal of the FSM

Double Buffer Control circuit is low which allows read/write operations

during reset. This will result in a cycle of false read/write

acknowledge signals following reset if the Transmit Request or Receive

Request signals are asserted. 

Change the QCnREQ value to $FF before resetting the IQUE module or

Double Buffer Controller. 

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. 

When an OC7M bit is set, an erroneous normal output compare event can 

happen on a timer port if the compare action is selected as "Timer 

disconnected from output pin logic ".

 

Corresponding configuration:

*  TIOSx = 1 --> Output compare mode

*  OMx = OLx = 0 --> Output compare logic disconnected from the pin

*  OC7Mx = 1 --> Mask bit set for OC7 event











 

Set OC7Mx = 1 only for channels where the output compare action should 

drive the pin, and OC7Mx = 0 for all other channels where the pin is 

required to be disconnected from the output compare logic. 

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 01.05 (05 

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.









 

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.