XC68HC705JJ7 Motorola, XC68HC705JJ7 Datasheet - Page 120

• Manufacturer Part Number: XC68HC705JJ7
• Description: MICROCONTROLLER
• Manufacturer: Motorola

Analog Subsystem
Advance Information
120
NOTE:
CPFR2
CPFR1
The CPFR1 and CPFR2 bits should be written with logic 1s following a
power-up of either comparator. This will clear out any latched CPF1 or
CPF2 flag bits which might have been set during the slower power-up
sequence of the analog circuitry.
If both inputs to a comparator are above the maximum common-mode
input voltage (V
and may set the comparator flag. Applying a reset to the device may only
temporarily clear this flag as long as both inputs of a comparator remain
above the maximum common-mode input voltages.
VOFF
Writing a logic 1 to this write-only flag clears the CPF2 flag in the ASR.
Writing a logic 0 to this bit has no effect. Reading the CPFR2 bit will
return a logic 0. By default, this bit looks cleared following a reset of
the device.
Writing a logic 1 to this write-only flag clears the CPF1 flag in the ASR.
Writing a logic 0 to this bit has no effect. Reading the CPFR1 bit will
return a logic 0. By default, this bit looks cleared after a reset of the
device.
This read-write bit controls the addition of an offset voltage to the
bottom of the sample capacitor. It is not active unless the OPT bit in
the COPR at location $1FF0 is set. Any reads of the VOFF bit location
return a logic 0 if the OPT bit is clear. During the time that the sample
capacitor is connected to an input (either HOLD or DHOLD set), the
bottom of the sample capacitor is connected to V
cleared by a reset of the device. For more information, see
Sample and
1 = Clears the CPF2 flag bit
0 = No effect
1 = Clears the CPF1 flag bit
0 = No effect
1 = Enables approximately 100 mV offset to be added to the
0 = Connects the bottom of the sample capacitor to V
sample voltage when both the HOLD and DHOLD control bits
are cleared
DD
Analog Subsystem
Hold.
–1.5 V), the output of the comparator is indeterminate
MC68HC705JJ7 • MC68HC705JP7 — REV 4
SS
. The VOFF bit is
SS
MOTOROLA
8.11