DSM2180F3 datasheet(23/63 Pages) STMICROELECTRONICS

23 / 63 page

23/63

DSM2180F3

Figure 11. Data Toggle Flowchart

The Error Flag (DQ5) bit is set if either an internal

time-out occurred while the embedded algorithm

attempted to program the byte, or if the DSP at-

tempted to program a 1 to a bit that was not erased

(not erased is logic 0).

It is suggested (as with all Flash memories) to read

the location again after the embedded program-

ming algorithm has completed, to compare the

byte that was written to Flash memory with the

byte that was intended to be written.

When using the Data Toggle method after an

Erase cycle, Figure 11 still applies. the Toggle

Flag (DQ6) bit toggles until the Erase cycle is com-

plete. A 1 on the Error Flag (DQ5) bit indicates a

time-out condition on the Erase cycle, a 0 indi-

cates no error. The DSP can read any location

within the sector being erased to get the Toggle

Flag (DQ6) bit and the Error Flag (DQ5) bit.

PSDsoft Express generates ANSI C code func-

tions which implement these Data Toggling algo-

rithms.

Erasing Flash Memory

Flash Bulk Erase. The Flash Bulk Erase instruc-

tion sequence uses six write operations followed

by a read operation of the status register, as de-

scribed in Table 5. If any byte of the Bulk Erase in-

struction sequence is wrong, the Bulk Erase

instruction sequence aborts and the device is re-

set to the Read Flash memory status. The Bulk

Erase command may be addresses to any one in-

dividual valid Flash memory segment (

FS0-FS7)

and the entire array (all segments) will be erased.

During a Bulk Erase, the memory status may be

checked by reading the Error Flag (DQ5) bit, the

Toggle Flag (DQ6) bit, and the Data Polling Flag

(DQ7) bit, as detailed in the section entitled “Pro-

gramming Flash Memory”, on page 21. The Error

Flag (DQ5) bit returns a 1 if there has been an

Erase Failure (maximum number of Erase cycles

have been executed).

It is not necessary to program the memory with

00h because the device automatically does this

before erasing to 0FFh.

During execution of the Bulk Erase instruction se-

quence, the Flash memory does not accept any in-

struction sequences.

The address provided with the Flash Bulk Erase

command sequence (Table 5) may select any one

of the eight internal Flash memory Sector Select

signals (FS0 - FS7). An erase of the entire Flash

memory array will occur even though the com-

mand was sent to just one Flash memory sector.

Flash Sector Erase. The Sector Erase instruc-

tion sequence uses six write operations, as de-

scribed in Table 5. Additional Flash Sector Erase

codes and Flash memory sector addresses can be

written subsequently to erase other Flash memory

sectors in parallel, without further coded cycles, if

the additional bytes are transmitted in a shorter

time than the time-out period of about 100 µs. The

input of a new Sector Erase code restarts the time-

out period.

The status of the internal timer can be monitored

through the level of the Erase Time-out Flag (DQ3)

bit. If the Erase Time-out Flag (DQ3) bit is 0, the

Sector Erase instruction sequence has been re-

ceived and the time-out period is counting. If the

Erase Time-out Flag (DQ3) bit is 1, the time-out

period has expired and the device is busy erasing

the Flash memory sector(s). Before and during

Erase time-out, any instruction sequence other

than Suspend Sector Erase and Resume Sector

Erase instruction sequences abort the cycle that is

currently in progress, and reset the device to Read

Array mode. It is not necessary to program the

Flash memory sector with 00h as the device does

this automatically before erasing (byte=FFh).

During a Sector Erase, the memory status may be

checked by reading the Error Flag (DQ5) bit, the

Toggle Flag (DQ6) bit, and the Data Polling Flag

(DQ7) bit, as detailed in the section entitled “Pro-

gramming Flash Memory”, on page 21.

During execution of the Erase cycle, the Flash

memory accepts only Reset and Suspend Sector

Erase instruction sequences. Erasure of one

READ

DQ5 & DQ6

START

READ DQ6

FAIL

PASS

AI01370B

DQ6

TOGGLE

YES

DQ5

= 1

YES

DQ6

TOGGLE

DSM2180F3 датащи(PDF) 23 Page - STMicroelectronics

DSM2180F3 датащи(HTML) 23 Page - STMicroelectronics

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 51 52 53 54 55 56 57 58 59 60 61 62 63

датащи скачать

ссылки URL