AM93LC86
16384-bits Serial Electrically Erasable PROM
(Preliminary)
Anachip Corp.
www.anachip.com.tw
Rev 0.1 Oct 20, 2003
5/12
Functional Description
Erase/write enable (EWEN)
Before any device programming (WRITE, WRAL,
ERASE, and ERAL) can be done, the EWEN
instruction must be executed first. When Vcc is
applied, this device powers up in the EWDS state.
The device then remains in a erase/write disable
(EWDS) state until a EWEN instruction is executed.
Thereafter the device remains enabled until a
EWDS instruction is executed or until Vcc is
removed. (shown in Figure 4)
Note: Neither the EWEN nor the EWDS instruction
has any effect on the READ instruction.
Erase/write disable (EWDS)
The
erase/write
disable
(EWDS)
instruction
disables all programming capabilities. This protects
the entire part against accidental modification of
data until a EWEN instruction is executed. (When
Vcc is applied, this part powers up in the EWDS
state.) To protect data, a EWDS instruction should
be executed upon completion of each programming
operation.
Note:
Neither the EWEN nor the EWDS instruction has any effect on
the READ instruction. (shown in figure 5)
Write (WRITE)
The WRITE instruction includes 8-bit or 16-bit of
data to be written into the specified register. After
the last data bit has been applied to DI, and before
the next rising edge of SK, CS must be brought low.
The falling edge of CS initiates the self-timed
programming cycle. After a minimum wait of 250ns
(5V operation) from the falling edge of CS (tcs), DO
will indicate the READY/BUSY status of the chip if
CS is brought HIGH. This means that logical "0"
implies the programming is still in progress while
logical "1" indicates the selected register has been
written, and the part is ready for another instruction.
(shown in figure 6)
Note:
The combination of CS HIGH, DI HIGH and the rising edge of
the SK clock, resets the READY/BUSY flag. Therefore, it is
important if you want to access the READY/BUSY flag, not to
reset it through this combination of control signals.
Before a WRITE instruction can be executed, the
device must be in the Write enable (WEN) state.
Write all (WRAL)
The Write All (WRAL) instruction programs all
registers with the data pattern specified in the
instruction. While the WRAL instruction is being
loaded, the address field becomes a sequence of
DON'T-CARE bits. (Shown in Figure 7)
As with the WRITE instruction, if CS is brought
HIGH after a minimum wait of 250ns (tcs), the DO
pin indicates the READY/BUSY status of the chip.
(shown in figure 7)
Erase (ERASE)
After the erase instruction is entered, CS must be
brought LOW. The falling edge of CS initiates the
self-timed internal programming cycle. Bringing CS
HIGH after minimum of tcs, will cause DO to
indicate the READ/BUSY status of the chip. To
explain this, a logical "0" indicates the programming
is still in progress while a logical "1" indicates the
erase cycle is complete and the part is ready for
another instruction. (shown in figure 8)
Erase all (ERAL)
Full chip erase is provided for ease of programming.
Erasing the entire chip involves setting all bits in the
entire memory array to a logical "1". (shown in
figure 9)