Operation

MC3PHAC Monolithic Intelligent Motor Controller, Rev. 2

Freescale Semiconductor

23

Maximum voltage

$0075

R/W

1

Maximum allowable modulation index

value

%Maximum voltage = value/$FF

$00–$FF

(5), (10)

$0079

R

2

DC bus voltage reading

$000–$3FF

Fault timeout

$006A

R/W

2

Specifies the delay time after a fault

condition before re-enabling the

motor.

Fault timeout = value * 0.262 sec

$0000–$FFFF

Fault timer

$006D

R

2

Real-time display of the fault timer

Elapsed fault time = value * 0.262 sec

$0000–$FFFF

(10)

$00C9

R/W

2

reduced deceleration.

$0000–$03FF

$0064

R/W

2

the RBRAKE pin being asserted.

$0000–$03FF

$0066

R/W

2

an under voltage fault.

$0000–$03FF

$0068

R/W

2

an over voltage fault.

$0000–$03FF

Speed in ADC

$0095

R

2

Left justified 10-bit ADC reading of the

SPEED input pin.

$0000–$FFC0

$00AE

R

1

Bit field indicating which setup

parameters have been initialized

before motion is permitted

$E0–$FF

$0001

R

1

Bit field indicating the current state of

the start/stop and forward/reverse

switches

$00–$FF

$FE01

R

1

Indicates cause of the last reset

$00–$FF

Version

$EE00

R

4

MC3PHAC version

ASCII field

1. The commanded PWM frequency cannot be written until the PWM outputs exit the high-impedance state. The default PWM

frequency is 15.873 kHz.

2. The PWM output pins remain in a high-impedance state until this parameter is specified.

3. This parameter must be specified before motor motion can be initiated by the MC3PHAC.

4. This is a write-once parameter. The first write to this address will execute normally. Further attempts at writing this

parameter will result in an illegal operation response from the MC3PHAC.

5. The value of this parameter is not valid until the PWM outputs exit the high-impedance state.

6. The data in this field is only valid for one read. Further reads will return a value of $00.

7. See register bit descriptions following this table.

8. Acceleration is an unsigned value with the upper seven bits range of $00 to $7F = acceleration value of 0 to

127 Hertz/second. The lower nine bits constitute the fractional portion of the acceleration parameter. Its range is $000 to

$1FF which equals 0 to ~1. Therefore, the range of acceleration is 0 to 127.99 Hertz/second.

9. Commanded motor frequency and actual frequency are signed values with the upper byte range of

$00 to $7F = frequency of 0 to 127 Hz. The lower byte is the fractional portion of the frequency. Its range is $00 to $FF

which equals 0 to ~1.

Table 6. User Interface Variables for Use with PC Master Software (Continued)

Name

Address

Read/

Write

Size

(Bytes)

Description

Valid Data