AM28F010A datasheet(18/35 Pages) AMD

18 / 35 page

Am28F010A

This detailed information is for your reference. It may

prove easier to always issue the Reset command two

consecutive times. This eliminates the need to deter-

mine if you are in the Setup Program state or not.

In-System Programming Considerations

Flash memories can be programmed in-system or in a

standard PROM programmer. The device may be sol-

dered to the circuit board upon receipt of shipment and

programmed in-system. Alternatively, the device may

initially be programmed in a PROM programmer prior

to soldering the device to the circuit board.

Auto Select Command

AMD’s Flash memories are designed for use in appli-

cations where the local CPU alters memory contents.

In order to correctly program any Flash memories

in-system, manufacturer and device codes must be

accessible while the device resides in the target

system. PROM programmers typically access the sig-

nature codes by raising A9 to a high voltage. However,

multiplexing high voltage onto address lines is not a

generally desired system design practice.

The device contains an Auto Select operation to supple-

ment traditional PROM programming methodologies.

The operation is initiated by writing 80h or 90h into the

command register. Following this command, a read

cycle address 0000h retrieves the manufacturer code of

01h (AMD). A read cycle from address 0001h returns

the device code (see the Auto Select Code table of the

corresponding device data sheet). To terminate the op-

eration, it is necessary to write another valid command,

such as Reset (00h or FFh), into the register.

AM28F010A Datasheet(PDF) 18 Page - Advanced Micro Devices