Document Number: 002-00948 Rev. *C
S29CD032J
S29CD016J
S29CL032J
S29CL016J
7. Device Operations
This section describes the read, program, erase, simultaneous read/write operations, and reset features of the Flash devices.
Operations are initiated by writing specific commands or a sequence with specific address and data patterns into the command
register (see
). The command register itself does not occupy any addressable memory location; rather, it is composed of
latches that store the commands, along with the address and data information needed to execute the command. The contents of the
register serve as input to the internal state machine; the state machine outputs dictate the function of the device. Writing incorrect
address and data values or writing them in an improper sequence may place the device in an unknown state, in which case the
system must write the reset command in order to return the device to the reading array data mode.
7.1
Device Operation Table
The device must be set up appropriately for each operation.
describes the required state of each control pin for any
particular operation.
Legend
L = Logic Low = V
IL
, H = Logic High = V
IH
, X = Don’t care.
Notes
20. WP# controls the two outermost sectors of the top boot block or the two outermost sectors of the bottom boot block.
21. DQ0 reflects the sector PPB (or sector group PPB) and DQ1 reflects the DYB.
Table 5. Device Bus Operation
Operation
CE#
OE#
WE#
RESET#
CLK
ADV#
Addresses
Data
(DQ0–DQ31)
Read
L
L
H
H
X
X
A
IN
D
OUT
Asynchronous Write
L
H
L
H
X
X
A
IN
D
IN
Synchronous Write
L
H
L
H
A
IN
D
IN
Standby (CE#)
H
X
X
H
H
X
X
High-Z
Output Disable
L
H
H
H
X
X
High-Z
High-Z
Reset
X
X
X
L
X
X
X
High-Z
PPB Protection Status (Note 2)
L
L
H
H
X
X
Sector Address,
A9 = V
ID
,
A7 – A0 = 02h
00000001h, (protected)
A6 = H
00000000h (unprotect)
A6 = L
Burst Read Operations
Load Starting Burst Address
L
X
H
H
A
IN
X
Advance Burst to next address
with appropriate Data presented
on the Data bus
L
L
H
H
H
X
Burst Data Out
Terminate Current Burst Read Cycle
H
X
H
H
X
X
High-Z
Terminate Current Burst
Read Cycle with RESET#
X
X
H
L
X
X
X
High-Z
Terminate Current Burst Read Cycle;
Start New Burst Read Cycle
L
H
H
H
A
IN
X
