Motorola M68EVB912B32, User Manual

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EEPROM BOOTLOADER
68EVB912B32UM/D E-3
(P)rogram
In Flash programming mode, the bootloader sends an ASCII "*" (asterisk character) to the host
computer, indicating that it is ready to receive an S-Record. The host then sends a single
S-Record and waits for the "*" prompt from the bootloader before sending the next S-Record.
This process is repeated until the bootloader receives an end-of-file (S9) record from the host
computer. If no S9 record is received, the bootloader continues to wait for another S-Record
indefinitely. In this situation, the EVB must be reset to return to the bootloader’s prompt
(S-Records already loaded into Flash EEPROM are unaffected by the missing S9 record;
reprogramming is not necessary).
If a Flash EEPROM location fails to program properly, the message "
Not Programmed
" is
displayed, and the bootloader’s prompt is redisplayed.
If an error occurs during programming, see the CAUTION on page E-3. If errors persist, the
problem may be caused by an S-Record containing data that is outside the range of the available
Flash EEPROM. The S-Record data must be within the range $8000 - $F7FF.
(L)oadEE
This selection causes a bulk erase of byte-erasable EEPROM in the address range $0D00 -
$0FFF. After the erase operation, a verify operation checks for proper erasure of all locations. If
any locations were found to contain a value other than $FF, the message "
Not Erased
" is
displayed, and the bootloader’s prompt is redisplayed.
If the erase operation was successful, the bootloader sends an ASCII "*" (asterisk character) to
the host computer, indicating that it is ready to receive an S-Record. The host then sends a single
S-Record and waits for the "*" prompt from the bootloader before sending the next S-Record.
This process is repeated until the bootloader receives an end-of-file (S9) record from the host
computer. If no S9 record is received, the bootloader continues to wait for another S-Record
indefinitely. In this situation, the EVB must be reset to return to the bootloader’s prompt
(S-Records already loaded into EEPROM are unaffected by the missing S9 record;
reprogramming is not necessary).
In case of errors during the
(L)oadEE
procedure, repeat the process several times. If the errors
persist, it is possible that the MCU may be damaged.
VECTOR JUMP TABLE: INTERRUPT AND RESET ADDRESSES
The CPU’s interrupt and reset vectors are located in the erase-protected area of Flash EEPROM
and thus cannot be reprogrammed with the S-Record bootloader.