mcf51em256 Freescale Semiconductor, Inc, mcf51em256 Datasheet - Page 38

• Manufacturer Part Number: mcf51em256
• Description: Microcontrollers Covers Mcf51em256 Mcf51em128
• Manufacturer: Freescale Semiconductor, Inc

1
2
3
4
Electrical Characteristics
2.12.1
38
Num
Typical values are based on characterization data at V
This is the shortest pulse that is guaranteed to be recognized as a reset pin request. Shorter pulses are not guaranteed to
override reset requests from internal sources.
This is the minimum pulse width that is guaranteed to pass through the pin synchronization circuitry. Shorter pulses may or may
not be recognized. In stop mode, the synchronizer is bypassed so shorter pulses can be recognized in that case.
Timing is shown with respect to 20% V
1
2
3
4
5
6
7
8
9
C
D
D
D
D
D
D
D
D
D
Control Timing
Bus frequency (t
Internal low-power oscillator period
External reset pulse width
(t
Reset low drive
Active background debug mode latch setup time
Active background debug mode latch hold time
IRQ pulse width
KBIPx pulse width
Port rise and fall time (load = 50 pF)
cyc
Slew rate control disabled (PTxSE = 0), low drive
Slew rate control disabled (PTxSE = 0), low drive
Slew rate control enabled (PTxSE = 1), low drive
Slew rate control enabled (PTxSE = 1), low drive
= 1/f
RESET PIN
Self_reset
MCF51EM256 Series ColdFire Microcontroller Data Sheet, Rev.3
cyc
)
= 1/f
Parameter
Preliminary—Subject to Change Without Notice
Bus
DD
2
)
and 80% V
Asynchronous path
Asynchronous path
Synchronous path
Synchronous path
Table 19. Control Timing
Figure 15. Reset Timing
4
DD
DD
levels. Temperature range –40 °C to 105 °C.
= 5.0 V, 25 °C unless otherwise stated.
2
3
2
3
t
extrst
t
t
t
Symbol
ILIH,
ILIH,
Rise
t
t
t
MSSU
t
t
rstdrv
f
extrst
MSH
LPO
Bus
, t
t
t
IHIL
IHIL
Fall
1.5 × t
1.5 × t
66 × t
Min
700
100
500
100
100
100
DC
—
—
cyc
cyc
cyc
Typical
11
35
40
75
—
—
—
Freescale Semiconductor
1
25.165
1300
Max
—
—
—
—
—
—
MHz
Unit
μs
ns
ns
ns
ns
ns
ns
ns