Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Software Design

Current measurement and current calibration when PWM is OFF

Before testing of the start switch, dc-bus current is measured when PWM is OFF. This way the dc-bus current measurement path is calibrated. The calibrated value Offset0_Curr is used for the final current calculation.

This offset on the ADC input should ideally be 1.65 V at 0 dc-bus current.

If the sensed value exceeds the limit (Offset_Max_Curr) when PWM is OFF, this indicates some hardware error, and the control flow enters into the fault state:

Start condition test

The start condition is tested. If in manual mode (PCMode = 0), the start condition is a movement in the switch from stop to start. In PC master software mode (PCMode = 1), the start condition in switch start position and StartCtrl = 1. If start condition valid then Strt_F is set, Stop_F is cleared, and the next state entered.

Designer Reference Manual

 

DRM028 — Rev 0

 

 

 

92

Software Design

MOTOROLA

 

For More Information On This Product,

 

 

Go to: www.freescale.com

 

Page 92
Image 92
Motorola M68HC08 manual Freescale Semiconductor, Inc