AM29SL800C Datasheet, PDF (8/41 Pages) Advanced Micro Devices – 8 Megabit (1 M x 8-Bit/512 K x 16-Bit) CMOS 1.8 Volt-only Super Low Voltage Flash Memory

PRELIMINARY
DEVICE BUS OPERATIONS
This section describes the requirements and use of the
device bus operations, which are initiated through the
internal command register. The command register it-
self does not occupy any addressable memory loca-
tion. The register is composed of latches that store the
commands, along with the address and data informa-
tion needed to execute the command. The contents of
the register serve as inputs to the internal state ma-
chine. The state machine outputs dictate the function of
the device. Table 1 lists the device bus operations, the
inputs and control levels they require, and the resulting
output. The following subsections describe each of
these operations in further detail.
Table 1. Am29SL800C Device Bus Operations
DQ8–DQ15
Read
Write
Operation
Standby
Output Disable
CE# OE# WE# RESET#
L
LH
H
L HL
H
V_CC ±
0.3 V
X
X
V_CC ±
0.3 V
L HH
H
Addresses
(Note 1)
A_IN
A_IN
X
X
DQ0–
DQ7
D_OUT
D_IN
BYTE#
= V_IH
D_OUT
D_IN
BYTE#
= V_IL
DQ8–DQ14 = High-Z,
DQ15 = A-1
High-Z High-Z
High-Z
High-Z High-Z
High-Z
Reset
X XX
L
X
High-Z High-Z
High-Z
Sector Address,
Sector Protect (Note 2)
L HL
V_ID
A6 = L, A1 = H,
D_IN
X
X
A0 = L
Sector Address,
Sector Unprotect (Note 2)
L HL
V_ID
A6 = H, A1 = H, D_IN
X
X
A0 = L
Temporary Sector Unprotect
X XX
V_ID
A_IN
D_IN
D_IN
High-Z
Legend:
L = Logic Low = V_IL, H = Logic High = V_IH, V_ID = 10 ± 1.0 V, X = Don’t Care, A_IN = Address In, D_IN = Data In, D_OUT = Data Out
Notes:
1. Addresses are A18:A0 in word mode (BYTE# = V_IH), A18:A-1 in byte mode (BYTE# = V_IL).
2. The sector protect and sector unprotect functions may also be implemented via programming equipment. See the “Sector
Protection/Unprotection” section.
Word/Byte Configuration
The BYTE# pin controls whether the device data I/O pins
DQ15–DQ0 operate in the byte or word configuration. If the
BYTE# pin is set at logic ‘1’, the device is in word configu-
ration, DQ15–DQ0 are active and controlled by CE# and
OE#.
If the BYTE# pin is set at logic ‘0’, the device is in byte con-
figuration, and only data I/O pins DQ0–DQ7 are active and
controlled by CE# and OE#. The data I/O pins DQ8–DQ14
are tri-stated, and the DQ15 pin is used as an input for the
LSB (A-1) address function.
Requirements for Reading Array Data
To read array data from the outputs, the system must drive
the CE# and OE# pins to V_IL. CE# is the power control and
selects the device. OE# is the output control and gates
array data to the output pins. WE# should remain at V_IH.
The BYTE# pin determines whether the device outputs
array data in words or bytes.
The internal state machine is set for reading array data
upon device power-up, or after a hardware reset. This en-
sures that no spurious alteration of the memory content oc-
curs during the power transition. No command is
necessary in this mode to obtain array data. Standard mi-
croprocessor read cycles that assert valid addresses on
the device address inputs produce valid data on the device
data outputs. The device remains enabled for read access
until the command register contents are altered.
See “Reading Array Data” for more information. Refer to
the AC Read Operations table for timing specifications and
to Figure 13 for the timing diagram. I_CC1 in the DC Charac-
teristics table represents the active current specification for
reading array data.
Writing Commands/Command Sequences
To write a command or command sequence (which in-
cludes programming data to the device and erasing sectors
of memory), the system must drive WE# and CE# to V_IL,
and OE# to V_IH.
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Am29SL800C