NEC 78K0 User Manual page 573

CHAPTER 31 ELECTRICAL SPECIFICATIONS ((A1) GRADE PRODUCTS)
Flash Memory Programming Characteristics:
= +10 to +60°C, 3.3 V ≤ V
(T
A
(1) Write erase characteristics
Parameter
V supply voltage
PP
V supply current
DD
V supply current
PP
Note 1
Step erase time
Note 2
Overall erase time
Note 3
Writeback time
Number of writebacks per 1
Note 4
writeback command
Number of erases/writebacks
Note 5
Step write time
Note 6
Overall write time per word
Note 7
Number of rewrites per chip
Notes 1. The recommended setting value of the step erase time is 0.2 s.
2. The prewrite time before erasure and the erase verify time (writeback time) are not included.
3. The recommended setting value of the writeback time is 50 ms.
4. Writeback is executed once by the issuance of the writeback command. Therefore, the number of retries
must be the maximum value minus the number of commands issued.
5. The recommended setting value of the step write time is 50
6. The actual write time per word is 100
included.
When a product is first written after shipment, "erase → write" and "write only" are both taken as one
7.
rewrite.
Example: P: Write, E: Erase
Shipped product
Shipped product → E → P → E → P → E → P: 3 rewrites
Remark The range of the operating clock during flash memory programming is the same as the range during normal
operation.
µ
PD78F0148(A1)
≤ 5.5 V, 3.3 V ≤ AV
= EV
DD DD
Symbol
V During flash memory programming
PP2
I When V = V
DD PP PP2
I V = V
PP PP PP2
T
er
T When step erase time = 0.2 s
era
T
wb
C When writeback time = 50 ms
wb
C
erwb
T
wr
When step write time = 50
T
wrw
byte)
C 1 erase + 1 write after erase = 1 rewrite
erwr
*
µ
s longer. The internal verify time during or after a write is not
→ P → E → P → E → P: 3 rewrites
User's Manual U15947EJ2V0UD
≤ V
, V = EV = AV
REF DD SS SS
Conditions
, f = 10 MHz, V = 5.5 V
XP DD
0.199
µ
s (1 word = 1
µ
s.
= 0 V)
SS
MIN. TYP. MAX.
9.7 10.0 10.3
37
100
0.2 0.201
20 s/chip
49.4 50 50.6
60 Times
16 Times
48 50 52
48 520
20 Times/
Unit
V
mA
mA
s
ms
µ
s
µ
s
area
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