UPD780138 Datasheet, PDF (485/558 Pages) NEC – 8-Bit Single-Chip Microcontrollers

CHAPTER 29 ELECTRICAL SPECIFICATIONS (STANDARD PRODUCTS, (A) GRADE PRODUCTS)
Flash Memory Programming Characteristics: Flash memory version
(TA = +10 to +60°C, 2.7 V ≤ VDD = EVDD ≤ 5.5 V, 2.7 V ≤ AVREF ≤ VDD, VSS = EVSS = AVSS = 0 V)
(1) Write erase characteristics
Parameter
VPP supply voltage
VDD supply current
VPP supply current
Step erase time^{Note 1}
Overall erase time^{Note 2}
Writeback time^{Note 3}
Number of writebacks per 1
writeback command^{Note 4}
Number of erases/writebacks
Step write time^{Note 5}
Overall write time per word^{Note 6}
Number of rewrites per chip^{Note 7}
Symbol
Conditions
VPP2
During flash memory programming
IDD
When VPP = VPP2, fXP = 10 MHz, VDD = 5.5 V
IPP
VPP = VPP2
Ter
Tera
When step erase time = 0.2 s
Twb
Cwb
When writeback time = 50 ms
MIN.
9.7
0.199
49.4
Cerwb
Twr
48
Twrw
When step write time = 50 µs (1 word = 1 48
byte)
Cerwr
1 erase + 1 write after erase = 1 rewrite
TYP.
10.0
0.2
50
50
MAX.
10.3
37
100
0.201
20
50.6
60
Unit
V
mA
mA
s
s/chip
ms
Times
16
Times
52
µs
520
µs
20 Times/
area
Notes 1.
2.
3.
4.
5.
6.
7.
The recommended setting value of the step erase time is 0.2 s.
The prewrite time before erasure and the erase verify time (writeback time) are not included.
The recommended setting value of the writeback time is 50 ms.
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.
The recommended setting value of the step write time is 50 µs.
The actual write time per word is 100 µs longer. The internal verify time during or after a write is not
included.
When a product is first written after shipment, “erase → write” and “write only” are both taken as one
rewrite.
Example: P: Write, E: Erase
Shipped product
→ P → E → P → E → P: 3 rewrites
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.
User’s Manual U16228EJ2V0UD
485