S93WD462/S93WD463
Ready/Busy Status
During the internal write operation the S93WD462/WD463 memory array is inaccessible. After starting the write
operation(takingCSlow)thehostcanimplementa10mstimeoutroutineoralternativelyitcanemployapollingroutine
that tests the state of the DO pin.
After starting the write, testing for the status is easily accomplished by taking CS high and testing the state of DO. If
it is low the device is still busy with the internal write. If it is high the write operation has completed.
For the polling routine the host has the option of toggling CS for each test of DO, or it can place CS high and then
intermittently test DO. SK is not required for any of these operations. Once the device is ready, it will continue to drive
DO high whenever the S93WD462/WD463 is selected. The ready state of DO can be cleared by clocking in a start
bit;thisstartbitcaneitherbethebeginningofanewcommandsequenceoritcanbeadummystartbitwithCSreturning
low before the host issues a new command.
SK
CS
STATUS VERIFY
t
CS
DI
t
t
SV
HZ
HIGH-Z
DO
BUSY
READY
HIGH-Z
STATUS CLEARED
t
EW
2029 ILL 13.0
2029-01 4/14/98
12
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
