tmp19a44fda TOSHIBA Semiconductor CORPORATION, tmp19a44fda Datasheet - Page 612

• Manufacturer Part Number: tmp19a44fda
• Description: 32bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

9)
Flash Memory Operation
Password
The password sequence received from the controller (5th to 16th bytes) is compared to the password
stored in the flash memory. All of the 12 bytes must match to pass the password check. Otherwise, a
password error occurs, which causes the boot program to return an error acknowledge in response to the
checksum byte (the 17th byte).
Following an echo-back of the command code, the boot program checks the contents of the 12-byte
password area (0x0000_0474 to 0x0000_047F) within the flash memory.
occurs. In this case, the boot program returns an error acknowledge (11H) in response to the checksum
byte (the 17th byte), regardless of whether the password sequence sent from the controller is all FFHs.
The RAM Transfer command (10H) causes the boot program to perform a password check.
If all these address locations contain the same bytes of data other than FFH, a password area error
The password check is performed even if the security function is enabled.
Fig. 24.6 Serial Operation Mode Determination Flow
Are all bytes the same?
tCD ← tAD − tAC
Password area error
Are all bytes equal to
UART Mode
tAB > tCD?
Start
Fig. 24.7 Password Area Check Flow
FFH?
Start
No
TMP19A44 (rev1.3)24-27
Yes
Yes
No
Yes
Password area is normal.
I/O Interface Mode
TMP19A44
2010-04-01