Datasheet

16 Mbit LPC Serial Flash

SST49LF016C

Data Sheet

Microchip Technology Company

Erase-Suspend/Erase-Resume Commands

The Erase Suspend command allows Sector-Erase or Block-Erase interruption in order to read or pro-

gram data in another block of memory. Once the Erase-Suspend command is executed, the device will

suspend any on-going Erase operation within time T

(10 µs). The device outputs status register data

when read after the Erase-Suspend command is written. The system is able to determine when the

Erase operation has been completed (WSMS=1) by polling the status register. After an Erase-Sus-

pend, the device will set the status register ESS bit (ESS=1) if the Erase has been successfully sus-

pended (refer to Table 10, “Software Status Register”). The Erase-Resume command resumes the

Erase operation that had been previously suspended.

After a successful Erase-Suspend, a Read-Array command may be written to read data from a Sector/

Block other than the suspended Sector/Block. A Program command sequence may also be issued dur-

ing Erase Suspend to program data in memory locations other than the Sector/Block currently in the

Erase-Suspend mode. If a Read-Array command is written to an address within the suspended Sector/

Block this may result in reading invalid data. If a Program command is written to an address within the

suspended Sector/Block the command is acknowledged but rejected. Other valid commands while

erase is suspended include Read-Status-Register, Read-Device-ID, and Erase-Resume.

The Erase-Resume command resumes the Erase process in the suspended sector or block. After the

Erase-Resume command is written, the device will continue the Erase process. Erase cannot resume

until any Program operation initiated during Erase-Suspend has completed. Suspended operations

cannot be nested: the system needs to complete or resume any previously suspended operation

before a new operation can be suspended. See Figure 8 for flowchart.

Program-Suspend/Program-Resume Command

The Program-Suspend and Program-Resume commands have no influence on the device. Since the

device requires a maximum of TBP (10 µs) in order to program a byte (see Table 28), when a Program-

Suspend command is written, the suspended Byte Program operation will always be successfully com-

pleted within the suspend latency time (TES =TBP = 10 µs).

Security ID Commands

The SST49LF016C device offers a 256-bit Security ID space. The Security ID space is divided into two

parts. One 64-bit segment is programmed at SST with a unique 64-bit number: this number cannot be

changed by the user. The other segment is 192-bit wide and is left blank: this space is available for

customers and can be programmed as desired.

The User-Security-ID-Program command is shown in Table 8, “Software Command Sequence”. Use

the memory addresses specified in Table 11 for Security ID programming. Once the customer segment

is programmed, it can be locked to prevent any alteration. The User-Security-ID-Program-Lockout

command is shown in Table 8, “Software Command Sequence”.

In order to read the Security ID information, the user can issue a Read Security ID Command (90H) to

the device. At this point the device enters the Read-Software-ID/Read-Security-ID mode. The Security

ID information can be read at the memory addresses in Table 11.

A Read-Array/Reset command (FFH) must then be issued to the device in order to exit the Read-Soft-

ware-ID/Read-Security-ID mode and return to Read-Array mode.

An alternate method to read the Security ID information is to read the Security ID registers located into

the register space as described in the “Security ID Registers” section.