CSR2930800BA datasheet(21/50 Pages) ETC

21 / 50 page

CSR2930800BA-90

DQ7

Data Polling

The CSR2930800BA devices feature Data Polling as a method to indicate to the host that the Embedded

Algorithms are in progress or completed. During the Embedded Program Algorithm an attempt to read the

devices will produce the complement of the data last written to DQ7. Upon completion of the Embedded Program

Algorithm, an attempt to read the device will produce the true data last written to DQ7. During the Embedded

Erase Algorithm, an attempt to read the device will produce a “0” at the DQ7 output. Upon completion of the

Embedded Erase Algorithm an attempt to read the device will produce a “1” at the DQ7 output. The flowchart

for Data Polling (DQ7) is shown in “3. Data Polling Algorithm” (s

FLOW CHART).

For chip erase and sector erase, the Data Polling is valid after the rising edge of the sixth WE pulse in the six

write pulse sequence. Data Polling must be performed at sector address within any of the sectors being erased

and not a protected sector. Otherwise, the status may not be valid. Once the Embedded Algorithm operation is

close to being completed, the CSR2930800BA data pins (DQ7) may change asynchronously while the output

enable (OE) is asserted low. This means that the devices are driving status information on DQ7 at one instant

of time and then that byte’s valid data at the next instant of time. Depending on when the system samples the

DQ7 output, it may read the status or valid data. Even if the device has completed the Embedded Algorithm

operation and DQ7 has a valid data, the data outputs on DQ0 to DQ6 may be still invalid. The valid data on DQ0

to DQ7 will be read on the successive read attempts.

The Data Polling feature is only active during the Embedded Programming Algorithm, Embedded Erase

Algorithm or sector erase time-out. (See “Hardware Sequence Flags Table”.)

See “6. AC Waveforms for Data Polling during Embedded Algorithm Operations” in s

SWITCHING WAVEFORMS

for the Data Polling timing specifications and diagrams.

10. DQ6

Toggle Bit I

The CSR2930800BA also feature the “Toggle Bit I” as a method to indicate to the host system that the Embedded

Algorithms are in progress or completed.

During an Embedded Program or Erase Algorithm cycle, successive attempts to read (OE toggling) data from

the devices will result in DQ6 toggling between one and zero. Once the Embedded Program or Erase Algorithm

cycle is completed, DQ6 will stop toggling and valid data will be read on the next successive attempts. During

programming, the Toggle Bit I is valid after the rising edge of the fourth WE pulse in the four write pulse sequence.

For chip erase and sector erase, the Toggle Bit I is valid after the rising edge of the sixth WE pulse in the six

write pulse sequence. The Toggle Bit I is active during the sector time out.

In programming, if the sector being written to is protected, the toggle bit will toggle for about 2

µs and then stop

toggling without the data having changed. In erase, the devices will erase all the selected sectors except for the

ones that are protected. If all selected sectors are protected, the chip will toggle the toggle bit for about 100 µs

and then drop back into read mode, having changed none of the data.

Either CE or OE toggling will cause the DQ6 to toggle. In addition, an Erase Suspend/Resume command will

cause the DQ6 to toggle.

See “7. AC Waveforms for Toggle Bit I during Embedded Algorithm Operations” in s

SWITCHING WAVEFORMS

for the Toggle Bit I timing specifications and diagrams.

11. DQ5

Exceeded Timing Limits

DQ5 will indicate if the program or erase time has exceeded the specified limits (internal pulse count). Under

these conditions DQ5 will produce a “1”. This is a failure condition which indicates that the program or erase

cycle was not successfully completed. Data Polling is the only operating function of the devices under this

condition. The CE circuit will partially power down the device under these conditions (to approximately 2 mA).

CSR2930800BA датащи(PDF) 21 Page - List of Unclassifed Manufacturers

CSR2930800BA датащи(HTML) 21 Page - List of Unclassifed Manufacturers

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

датащи скачать

ссылки URL