M36W832TE Datasheet, PDF (57/64 Pages) STMicroelectronics – 32 Mbit 2Mb x16, Boot Block Flash Memory and 8 Mbit 512Kb x16 SRAM, Multiple Memory Product

Figure 30. Erase Flowchart and Pseudo Code
M36W832TE, M36W832BE
Start
Write 20h
Write Block
Address & D0h
Read Status
Register
erase_command ( blockToErase ) {
writeToFlash (any_address, 0x20) ;
writeToFlash (blockToErase, 0xD0) ;
/* only A12-A20 are significannt */
/* Memory enters read status state after
the Erase Command */
do {
status_register=readFlash (any_address) ;
/* EF or GF must be toggled*/
NO
b7 = 1
YES
NO
b3 = 0
YES
YES
b4, b5 = 1
NO
NO
b5 = 0
YES
NO
b1 = 0
YES
End
VPPF Invalid
Error (1)
Command
Sequence Error (1)
Erase Error (1)
Erase to Protected
Block Error (1)
} while (status_register.b7== 0) ;
if (status_register.b3==1) /*VPPF invalid error */
error_handler ( ) ;
if ( (status_register.b4==1) && (status_register.b5==1) )
/* command sequence error */
error_handler ( ) ;
if ( (status_register.b5==1) )
/* erase error */
error_handler ( ) ;
if (status_register.b1==1) /*program to protect block error */
error_handler ( ) ;
}
AI90177b
Note: If an error is found, the Status Register must be cleared before further Program/Erase operations.
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