MC68HC705V12CFN MOTOROLA [Motorola, Inc], MC68HC705V12CFN Datasheet - Page 195

• Manufacturer Part Number: MC68HC705V12CFN
• Description: The Motorola microcontroller
• Manufacturer: MOTOROLA [Motorola, Inc]

15.6.3 Current Direction Registers
MC68HC705V12
MOTOROLA
—
Rev. 3.0
The theoretical current that will flow between the + and pins is given by
this equation:
I
and is given by this equation:
I
E
in
The E
17.11 Gauge Driver
The “reg value” is the base 10 representation of the value written to the
magnitude registers.
I
to generate the coil currents.
I
The bits in these registers control the direction of current flow in each of
the full eight H-bridge drive outputs. Note that only coil 2 in the minor
gauges requires a direction bit. Since coil 1 in each of the minor gauges
is a half H-bridge driver, it only requires a current magnitude register.
The CDR also contains a master and slave latch. A read of any of these
registers will return the value in the slave buffer.
CM
CM
MAX
MAX
CA
17.11 Gauge Driver
is the maximum current that can be driven into any of the coil drivers
= (I
is the total internal error in generating I
is set by the external resistor and is a reference current that is used
is related to the external R
MAX
MAX
is the error tolerance of the R
x 10) x (1 + E
Gauge Drivers
Electricals.
Electricals.
I
CA
=
I
MAX
+ E
ICM X
MAX
=
MAX
(
R
)
2.5
resistor by the equation:
MAX
Reg value
-------------------------- -
255
MAX
)
x 4
CM
resistor and is shown in
Gauge Driver Control Registers
from I
MAX
Advance Information
and is shown
Gauge Drivers
195