93AA46A/B/C, 93LC46A/B/C, 93C46A/B/C
The DO pin indicates the Ready/Busy status of the
device if CS is brought high after a minimum of 250 ns
2.9
Write All (WRAL)
The Write All (WRAL) instruction will write the entire
memory array with the data specified in the command.
For 93AA46A/B/C and 93LC46A/B/C devices, after the
last data bit is clocked into DI, the falling edge of CS
initiates the self-timed auto-erase and programming
cycle. For 93C46A/B/C devices, the self-timed auto-
erase and programming cycle is initiated by the rising
edge of CLK on the last data bit. Clocking of the CLK
pin is not necessary after the device has entered the
WRAL cycle. The WRAL command does include an
automatic ERAL cycle for the device. Therefore, the
WRALinstruction does not require an ERALinstruction,
but the chip must be in the EWEN status.
low (TCSL).
Note:
After the Write All cycle is complete,
issuing a Start bit and then taking CS low
will clear the Ready/Busy status from DO.
VCC must be ≥4.5V for proper operation of WRAL.
FIGURE 2-10:
WRAL TIMING FOR 93AA AND 93LC DEVICES
TCSL
CS
CLK
0
1
x
1
0
0
•••
Dx
•••
DI
x
D0
TSV
TCZ
High-Z
Busy Ready
DO
HIGH-Z
TWL
VCC must be ≥4.5V for proper operation of WRAL.
FIGURE 2-11:
WRAL TIMING FOR 93C DEVICES
TCSL
CS
CLK
0
1
x
1
0
0
•••
Dx
•••
DI
x
D0
TSV
TCZ
High-Z
Busy Ready
DO
HIGH-Z
TWL
© 2008 Microchip Technology Inc.
DS21749G-page 11
MICROCHIP [ MICROCHIP ]
