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Intel Advanced+ Boot Block Flash Memory (C3)
4.0
Modes of Operation
4.1
Read Mode
The flash memory has four read modes (read array, read identifier, read status, and CFI query), and
two write modes (program and erase). Three additional modes (erase suspend to program, erase
suspend to read, and program suspend to read) are available only during suspended operations.
Table 7, “Command Bus Operations” on page 24 and Table 8, “Command Codes and
Descriptions” on page 25 summarize the commands used to reach these modes. Appendix A,
“Write State Machine States” on page 50 is a comprehensive chart showing the state transitions.
4.1.1
Read Array
When RP# transitions from V (reset) to V , the device defaults to read-array mode and will
IL
IH
respond to the read-control inputs (CE#, address inputs, and OE#) without any additional CUI
commands.
When the device is in read array mode, four control signals control data output.
• WE# must be logic high (V )
IH
• CE# must be logic low (V )
IL
• OE# must be logic low (V )
IL
• RP# must be logic high (V )
IH
In addition, the address of the desired location must be applied to the address pins. If the device is
not in read-array mode, as would be the case after a Program or Erase operation, the Read Array
command (0xFF) must be issued to the CUI before array reads can occur.
4.1.2
Read Identifier
The read-identifier mode outputs three types of information: the manufacturer/device identifier, the
block locking status, and the protection register. The device is switched to this mode by issuing the
Read Identifier command (0x90). Once in this mode, read cycles from addresses shown in Table 6
retrieve the specified information. To return to read-array mode, issue the Read Array command
(0xFF).
Datasheet
19
INTEL [ INTEL ]
