MC68HC908MR8 Datasheet, PDF (345/372 Pages) Motorola, Inc – Microcontrollers

Electrical Specifications
Memory Characteristics
21.7 Memory Characteristics
Characteristic
Symbol
Min
Typ
Max
Unit
RAM data retention voltage
FLASH program bus clock frequency
V_RDR
1.3
—
—
1
—
—
V
—
MHz
FLASH read bus clock frequency
f_Read(1)
32k
—
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
—
—
µs
FLASH high-voltage hold time
t_nvh
5
—
—
µs
FLASH high-voltage hold time (mass erase)
t_nvhl
100
—
—
µs
FLASH program hold time
t_pgs
5
—
—
µs
FLASH program time
t_PROG
30
—
40
µs
FLASH return to read time
t_rcv(4)
1
—
—
µs
FLASH cumulative program HV period
t_HV(5)
—
—
4
ms
FLASH row erase endurance⁽⁶⁾
—
10k
100k⁽⁷⁾
—
Cycles
FLASH row program endurance⁽⁸⁾
—
10k
100k⁽⁷⁾
—
Cycles
FLASH data retention time⁽⁹⁾
—
10
100⁽¹⁰⁾
—
Years
Notes:
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 clearing
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. FLASH endurance is a function of the temperature at which erasure occurs. Typical endurance degrades when the tem-
perature while erasing is less than 25°C.
8. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at
least this many erase / program cycles.
9. The FLASH is guaranteed to retain data over the entire operating temperature range for at least the minimum
time specified.
10. Freescale performs reliability testing for data retention. These tests are based on samples tested at elevated tempera-
tures. Due to the higher activation energy of the elevated test temperature, calculated life tests correspond to more than
100 years of operation/storage at 55°C
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor
Electrical Specifications
Technical Data
345