公开(公告)号：US5592641A

公开(公告)日：1997-01-07

申请号：US85546

申请日：1993-06-30

申请人： Mickey L. Fandrich ,  Salim B. Fedel ,  Thomas C. Price ,  Richard J. Durante ,  Geoffrey A. Gould ,  Timothy W. Goodell ,  Scott M. Doyle

发明人： Mickey L. Fandrich ,  Salim B. Fedel ,  Thomas C. Price ,  Richard J. Durante ,  Geoffrey A. Gould ,  Timothy W. Goodell ,  Scott M. Doyle

IPC分类号： G11C7/24 ,  G11C16/22 ,  G06F12/14

CPC分类号： G11C16/22 ,  G11C7/24

摘要： A method and device for selectively enabling and disabling write access to flash blocks in a flash memory device. A lock command locks and unlocks a flash block in a flash array containing a plurality of flash blocks. A block data row decoder selects a block data area of the flash block, and a block status row decoder selects a block status area of the flash block. A lock bit in the block status area is programmed to a first logic state if the lock command specifies a lock flash block operation, or to a second logic state if the lock command specifies a release flash block operation. If a write protect input, read from the write protect pin of the flash memory device, indicates that a write lock is enabled and if a block enabled status bit in a block status register corresponding to the block indicates that the block has the write lock, then the lock bit is read and stored into the block enabled status bit in the block status register corresponding to the block. The write protect input is read again from the write protect pin and if the write protect input indicates that the write lock is enabled, and if the block enabled status bit in the block status register corresponding to the block, as updated, indicates that the block has the write lock, then an error is signaled.

摘要翻译： 一种用于选择性地启用和禁用对闪存设备中的闪存块的写入访问的方法和设备。 锁定命令锁定并解锁包含多个闪存块的闪存阵列中的闪存块。 块数据行解码器选择闪存块的块数据区，块状态行解码器选择闪存块的块状态区。 如果锁定命令指定锁定闪存块操作，则块状态区域中的锁定位被编程为第一逻辑状态，如果锁定命令指定释放闪存块操作，则将其锁定到第二逻辑状态。 如果写保护输入从闪存器件的写保护引脚读取，则指示写锁定被使能，并且如果与该块相对应的块状态寄存器中的块使能状态位指示该块具有写锁定， 则锁定位被读取并存储到与块相对应的块状态寄存器中的块使能状态位。 写保护输入再次从写保护引脚读取，如果写保护输入指示写锁定使能，并且如果块状态寄存器中对应于块更新的块状态寄存器位指示块 有写锁定，然后发出错误信号。