M28W320CT, M28W320CB
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Figure 27. Protection Register Program Flowchart and Pseudo Code
Note: 1. Status check of b1 (Protected Block), b3 (V
PP
Invalid) and b4 (Program Error) can be made after each program operation or after
a sequence.
2. If an error is found, the Status Register must be cleared before further Program/Erase Controller operations.
Write C0h
AI04381
Start
Write Address
& Data
Read Status
Register
YES
NO
b7 = 1
YES
NO
b3 = 0
NO
b4 = 0
V
PP
Invalid
Error (1, 2)
Program
Error (1, 2)
protection_register_program_command (addressToProgram, dataToProgram) {:
writeToFlash (any_address, 0xC0) ;
do {
status_register=readFlash (any_address) ;
/* E or G must be toggled*/
} while (status_register.b7== 0) ;
if (status_register.b3==1) /*VPP invalid error */
error_handler ( ) ;
YES
End
YES
NO
b1 = 0
Program to Protected
Block Error (1, 2)
writeToFlash (addressToProgram, dataToProgram) ;
/*Memory enters read status state after
the Program Command*/
if (status_register.b4==1) /*program error */
error_handler ( ) ;
if (status_register.b1==1) /*program to protect block error */
error_handler ( ) ;
}
