A28F400BX-T B 4-MBIT (256K x16 512K x8) BOOT BLOCK.
A28F400BX-T - 4-MBIT BOOT BLOCK FLASH MEMORY
PA28F400BX - 4-MBIT BOOT BLOCK FLASH MEMORY
A28F400BX-B - 4-MBIT BOOT BLOCK FLASH MEMORY