Datasheet

Electrical Characteristics
MCF51AC256 ColdFire Microcontroller Data Sheet, Rev.7
Freescale Semiconductor 39
2.14 EMC Performance
Electromagnetic compatibility (EMC) performance is highly dependant on the environment in which the
MCU resides. Board design and layout, circuit topology choices, location and characteristics of external
components as well as MCU software operation all play a significant role in EMC performance. The
system designer should consult Freescale applications notes such as AN2321, AN1050, AN1263,
AN2764, and AN1259 for advice and guidance specifically targeted at optimizing EMC performance.
2.14.1 Radiated Emissions
Microcontroller radiated RF emissions are measured from 150 kHz to 1 GHz using the TEM/GTEM Cell
method in accordance with the IEC 61967-2 and SAE J1752/3 standards. The measurement is performed
with the microcontroller installed on a custom EMC evaluation board while running specialized EMC test
software. The radiated emissions from the microcontroller are measured in a TEM cell in two package
orientations (North and East). For more detailed information concerning the evaluation results, conditions
and setup, please refer to the EMC Evaluation Report for this device.
Table 21. Flash Characteristics
Num C Characteristic Symbol Min Typical
1
1
Typical values are based on characterization data at V
DD
= 5.0 V, 25 C unless otherwise stated.
Max Unit
1 — Supply voltage for program/erase V
prog/erase
2.7 — 5.5 V
2 — Supply voltage for read operation V
Read
2.7 — 5.5 V
3 — Internal FCLK frequency
2
2
The frequency of this clock is controlled by a software setting.
f
FCLK
150 — 200 kHz
4 — Internal FCLK period (1/FCLK) t
Fcyc
5 — 6.67 s
5 — Byte program time (random location)
2
t
prog
9t
Fcyc
6 — Byte program time (burst mode)
2
t
Burst
4t
Fcyc
7 — Page erase time
3
3
These values are hardware state machine controlled. User code does not need to count cycles. This information
supplied for calculating approximate time to program and erase.
t
Page
4000 t
Fcyc
8 — Mass erase time
2
t
Mass
20,000 t
Fcyc
9C
Program/erase endurance
4
T
L
to T
H
= –40 C to 105 C
T = 25 C
4
Typical endurance for flash was evaluated for this product family on the 9S12Dx64. For additional information on
how Freescale Semiconductor defines typical endurance, please refer to Engineering Bulletin EB619/D, Typ i c a l
Endurance for Nonvolatile Memory.
— 10,000
—
—
100,000
—
—
cycles
10 C Data retention
5
5
Typical data retention values are based on intrinsic capability of the technology measured at high temperature and
de-rated to 25C using the Arrhenius equation. For additional information on how Freescale Semiconductor defines
typical data retention, please refer to Engineering Bulletin EB618/D, Typical Data Retention f or Nonv olatile Memory.
t
D_ret
15 100 — years