mcf51ac256 Freescale Semiconductor, Inc, mcf51ac256 Datasheet - Page 29

• Manufacturer Part Number: mcf51ac256
• Description: Mcf51ac256 Coldfire Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

1
2
3
4
2.11.1
Freescale Semiconductor
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)
Slew rate control disabled (PTxSE = 0), Low Drive
cyc
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
cyc
)
MCF51AC256 ColdFire Microcontroller Data Sheet, Rev.1
= 1/f
Parameter
Preliminary—Subject to Change Without Notice
Bus
DD
2
)
and 80% V
Asynchronous path
Asynchronous path
Synchronous path
Synchronous path
Table 17. Control Timing
Figure 9. 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 x t
1.5 x t
66 x t
Preliminary Electrical Characteristics
Min
800
100
500
100
100
100
dc
—
—
cyc
cyc
cyc
Typical
11
35
40
75
—
—
—
1
1500
Max
24
—
—
—
—
—
—
MHz
Unit
μs
ns
ns
ns
ns
ns
ns
ns
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