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Section 6 ROM
Rev. 6.00 Sep 12, 2006 page 133 of 526
REJ09B0326-0600
6.7.6
Erase Flowcharts and Sample Programs
Flowchart for Erasing One Block
Start
End of erase
Erase error
Set erase block register
(set bit for block to be erased to 1)
Write 0 data in all addresses to be erased
(prewrite)
*
1
Select erase mode
(E bit = 1 in FLMCR)
n = 1
Wait (x) ms
*
5
Clear E bit
Erasing halts
End of erase-verify
No
No
NG
No
OK
Yes
Yes
Yes
Enable watchdog timer
*
2
Disable watchdog timer
Select erase-verify mode
(EV bit = 1)
Dummy write to verify address
*
3
(flash memory latches
address)
Set block start address as
verify address
Wait (t
vs1
) µs
*
6
Wait (t
vs2
) µs
*
6
Clear EV bit
A 1
→
address
Clear EV bit
n + 1
→
n
Double the erase time
(x
×
2
→
x)
Clear erase block register
(clear bit for erased block to 0)
Verify
*
4
(read data H'FF?)
Last address?
n
≥
N?
*
6
n
>
4?
Notes: 1. Program all addresses to be erased by
following the prewrite flowchart.
2. Set the watchdog timer overflow interval to
the initial value shown in table 6.12.
3. For the erase-verify dummy write, write H'FF
using a byte transfer instruction.
4. For the erase-verify operation, read the data
using a byte transfer instruction. When
erasing multiple blocks, clear the erase block
register bits for erased blocks and perform
additional erasing only for unerased blocks.
5. Erase time x is successively incremented to
initial set value x 2n-1 (n = 1 to 4), and is
fixed from the 4th time onward. An initial
value of 6.25 ms or less should be set, and
the time for one erasure should be 50 ms or
less.
6. t
vs1
: 4 µs or more
t
vs2
: 2 µs or more
N:
602 (set N so that the total erase time
does not exceed 30 s)
Figure 6.14 Erase Flowchart
Summary of Contents for F-ZTAT H8/3642A Series
Page 6: ...Rev 6 00 Sep 12 2006 page iv of xx ...
Page 8: ...Rev 6 00 Sep 12 2006 page vi of xx ...
Page 22: ...Rev 6 00 Sep 12 2006 page xx of xx ...
Page 124: ...Section 5 Power Down Modes Rev 6 00 Sep 12 2006 page 102 of 526 REJ09B0326 0600 ...
Page 188: ...Section 6 ROM Rev 6 00 Sep 12 2006 page 166 of 526 REJ09B0326 0600 ...
Page 190: ...Section 7 RAM Rev 6 00 Sep 12 2006 page 168 of 526 REJ09B0326 0600 ...
Page 298: ...Section 9 Timers Rev 6 00 Sep 12 2006 page 276 of 526 REJ09B0326 0600 ...
Page 378: ...Section 12 A D Converter Rev 6 00 Sep 12 2006 page 356 of 526 REJ09B0326 0600 ...
Page 446: ...Section 13 Electrical Characteristics Rev 6 00 Sep 12 2006 page 424 of 526 REJ09B0326 0600 ...