mc68hc916y3 Freescale Semiconductor, Inc, mc68hc916y3 Datasheet - Page 152

• Manufacturer Part Number: mc68hc916y3
• Description: Mc68hc16y3 16 Bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

5-44
MOTOROLA
DATA15
DATA8
DATA7
DATA0
Alternate methods can be used for driving data bus pins low during reset. Figure 5-18
shows two of these options. The simplest is to connect a resistor in series with a diode
from the data bus pin to the RESET line. A bipolar transistor can be used for the same
purpose, but an additional current limiting resistor must be connected between the
base of the transistor and the RESET pin. If a MOSFET is substituted for the bipolar
transistor, only the 1 k
offer the protection from potential memory corruption during RESET assertion as does
the circuit shown in Figure 5-17.
RESET
R/W
DS
Figure 5-17 Preferred Circuit for Data Bus Mode Select Conditioning
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DD
V
DD
Freescale Semiconductor, Inc.
For More Information On This Product,
isolation resistor is required. These simpler circuits do not
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DD
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OUT1
IN1
HIGH OR LOW
AS NEEDED
TIE INPUTS
74HC244
OUT8
IN8
OE
OUT1
IN1
HIGH OR LOW
AS NEEDED
TIE INPUTS
74HC244
MC68HC16Y3/916Y3
DATA BUS SELECT CONDITIONING
USER’S MANUAL
OUT8
IN8
OE