P30
14.0
Special Read States
The following sections describe non-array read states. Non-array reads can be
performed in asynchronous read or synchronous burst mode. A non-array read
operation occurs as asynchronous single-word mode.
When non-array reads are performed in
asynchronous page mode only the first data is valid and all subsequent data are undefined. When a
non-
array read operation occurs as synchronous burst mode, the same word of data
requested will be output on successive clock edges until the burst length requirements
are satisfied.
Refer to the following waveforms for more detailed information:
•
•
•
14.1
Read Status Register
To read the Status Register, issue the Read Status Register command at any address.
Status Register information is available to which the Read Status Register, Word
Program, or Block Erase command was issued. Status Register data is automatically
made available following a Word Program, Block Erase, or Block Lock command
sequence. Reads from the device after any of these command sequences outputs the
device’s status until another valid command is written (e.g. Read Array command).
The Status Register is read using single asynchronous-mode or synchronous burst
mode reads. Status Register data is output on DQ[7:0], while 0x00 is output on
DQ[15:8]. In asynchronous mode the falling edge of OE#, or CE# (whichever occurs
first) updates and latches the Status Register contents. However, reading the Status
Register in synchronous burst mode, CE# or ADV# must be toggled to update status
data.
The Device Write Status bit (SR[7]) provides overall status of the device. Status
register bits SR[6:1] present status and error information about the program, erase,
suspend, V
PP
, and block-locked operations.
Table 32: Status Register Description (Sheet 1 of 2)
Status Register (SR)
Device Write
Status
DWS
7
Bit
7
6
5
4
Erase Suspend
Status
ESS
6
Name
Device Write Status (DWS)
Erase Suspend Status (ESS)
Erase Status (ES)
Program Status (PS)
Erase Status
ES
5
Program
Status
PS
4
V
PP
Status
VPPS
3
Program
Suspend
Status
PSS
2
Description
0 = Device is busy; program or erase cycle in progress; SR[0] valid.
1 = Device is ready; SR[6:1] are valid.
0 = Erase suspend not in effect.
1 = Erase suspend in effect.
0 = Erase successful.
1 = Erase fail or program sequence error when set with SR[4,7].
0 = Program successful.
1 = Program fail or program sequence error when set with SR[5,7]
Default Value = 0x80
Block-Locked
Status
BLS
1
BEFP
Status
BWS
0
November 2007
Order Number: 306666-11
Datasheet
69
NUMONYX [ NUMONYX B.V ]
