Electrical Specifications
FLASH Memory Characteristics
MC68HC908MR16/MC68HC908MR32
—
Rev. 5.0
Advance Information
MOTOROLA
Electrical Specifications
373
22.7 FLASH Memory Characteristics
Characteristic
Symbol/
Description
Min
Max
Units
RAM data retention voltage
V
RDR
1.3
—
V
FLASH program bus clock frequency
—
1
—
MHz
FLASH read bus clock frequency
f
Read(1)
1. f
Read
is defined as the frequency range for which the FLASH memory can be read.
2. If the page erase time is longer than t
Erase
(min), there is no erase-disturb, but it reduces the endurance of the FLASH
memory.
3. If the mass erase time is longer than t
MErase
(min), there is no erase-disturb, but it reduces the endurance of the FLASH
memory.
4. t
RCV
is defined as the time it needs before the FLASH can be read after turning off the high voltage charge pump, by clear-
ing HVEN to logic 0.
5.
t
HV
is defined as the cumulative high voltage programming time to the same row before next erase.
t
HV
must satisfy this condition: t
NVS
+ t
NVH
+ t
PGS
+ (t
PROG
×
64)
≤
t
HV
max.
6. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase/program cycles.
7. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase/program cycles.
8. The FLASH is guaranteed to retain data over the entire operating temperature range for at least the minimum
time specified.
32 k
8.4 M
Hz
FLASH page erase time
t
Erase(2)
1
—
ms
FLASH mass erase time
t
MErase(3)
4
—
ms
FLASH PGM/Erase to HVEN set up time
t
NVS
10
—
μ
s
FLASH high-voltage hold time
t
NVH
5
—
μ
s
FLASH high-voltage hold time (mass erase)
t
NVHL
100
—
μ
s
FLASH program hold time
t
PGS
5
—
μ
s
FLASH program time
t
PROG
30
40
μ
s
FLASH return to read time
t
RCV(4)
1
—
μ
s
FLASH cumulative program HV period
t
HV(5)
—
4
ms
FLASH row erase endurance
(6)
—
10 k
—
Cycles
FLASH row program endurance
(7)
—
10 k
—
Cycles
FLASH data retention time
(8)
—
10
—
Years