
L29S800F 
PRELIMINARY 
A 
8MEGABIT (1M×8 /512K×16)
3 VOLT CMOS FLASH MEMERY 
LinkSmart 
24                                      
 071802
Mode
DQ
7
DQ
6
DQ
2
Program 
7
DQ
Toggle 
1 
Erase 
0 
Toggle 
Toggle 
Erase-Suspend Read 
(Erase-Suspended Sector) 
(Note 1) 
1 
1 
Toggle 
Erase-Suspend Program 
7
DQ
Toggle (Note 1) 
1 (Note 2) 
Notes: 
1. Performing successive read operations from any address will cause DQ
6
 to toggle. 
2. Reading the byte address being programmed while in the erase-suspend program mode will indicate 
logic “1” at the DQ
2
 bit. However, successive reads from the erase-suspended sector will cause DQ
2
to toggle. 
RY/
BY
Ready/Busy 
The L29S800F/-B provide a RY/
BY
  open-drain output pin as a way to indicate to the host system that the 
Embedded Algorithms are either in progress or has been completed. If the output is low, the devices are 
busy with either a program or erase operation. If the output is high, the devices are ready to accept any 
read/write or erase operation. When the RY/
BY
  pin is low, the devices will not accept any additional 
program or erase commands. If the L29S800F/-B are placed in an Erase Suspend mode, the RY/
BY
 output 
will be high. 
During programming, the RY/
BY
  pin is driven low after the rising edge of the fourth 
WE
 pulse. During an 
erase operation, the RY/
BY
  pin is driven low after the rising edge of the sixth 
WE
 pulse. The RY/
BY
  pin 
will indicate a busy condition during the 
RESET
  pulse. Refer to Figure 11 and 12 for a detailed timing 
diagram. The RY/
BY
  pin is pulled high in standby mode. 
Since this is an open-drain output, RY/
BY
  pins can be tied together in parallel with a pull-up resistor to 
V
CC
. 
Byte/Word Configuration 
The 
BYTE
 pin selects the byte (8-bit) mode or word (16-bit) mode for the L29S800F/-B devices. When this 
pin is driven high, the devices operate in the word (16-bit) mode. The data is read and programmed at DQ
0 
to DQ
15
. When this pin is driven low, the devices operate in byte (8-bit) mode. Under this mode, the 
DQ
15
/A
-1
 pin becomes the lowest address bit and DQ
8
 to DQ
14
 bits are tri-stated. However, the command 
bus cycle is always an 8-bit operation and hence commands are written at DQ
0
 to DQ
7
 and the DQ
8
 to DQ
15
bits are ignored. Refer to Figures 13, 14 and 15 for the timing diagram. 
Data Protection 
The L29S800F/-B are designed to offer protection against accidental erasure or programming caused by 
spurious system level signals that may exist during power transitions. During power up the devices 
automatically reset the internal state machine in the Read mode. Also, with its control register architecture, 
alteration of the memory contents only occurs after successful completion of specific multi-bus cycle 
command sequences. 
The devices also incorporate several features to prevent inadvertent write cycles resulting form V
CC
power-up and power-down transitions or system noise.