Memory Characteristics
MC68HC908JL3E Family Data Sheet, Rev. 4
Freescale Semiconductor
145
16.13 Memory Characteristics
Table 16-11. Memory Characteristics
Characteristic
Symbol
Min
Max
Unit
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 mem-
ory.
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 clearing
HVEN to 0.
5. tHV 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
×
32)
≤
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.
32k
8M
Hz
Flash page erase time
t
Erase(2)
1
—
ms
Flash mass erase time
t
MErase(3)
t
nvs
t
nvh
t
nvh1
t
pgs
t
PROG
4
—
ms
Flash PGM/ERASE to HVEN set up time
10
—
μ
s
Flash high-voltage hold time
5
—
μ
s
Flash high-voltage hold time (mass erase)
100
—
μ
s
Flash program hold time
5
—
μ
s
Flash program time
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)
—
10k
—
cycles
Flash row program endurance
(7)
—
10k
—
cycles
Flash data retention time
(8)
—
10
—
years