8XC196MC, MD, MH USER’S MANUAL

9.4PROGRAMMING THE WAVEFORM GENERATOR

This section explains how to configure the waveform generator and determine its status.

9.4.1Configuring the Outputs

The waveform generator’s outputs are multiplexed with general-purpose output port 6, so you must configure them as special-function signals to use them as waveform-generator outputs. The WG_OUTPUT register (Figure 9-8) configures the pins, establishes the output polarity, and con- trols whether changes to the outputs are synchronized with an event or take effect immediately.

Four bits of WG_OUTPUT are unrelated to the waveform generator; they configure the outputs for the pulse-width modulator (PWM) peripheral, which also shares pins with port 6. The P6 and PE6 bits control the P6.6/PWM0 pin, and the P7 and PE7 bits control the P6.7/PWM1 pin. Their placement in this register allows you to configure all the port 6 pins with a single write to WG_OUTPUT.

Table 9-5 shows the bit combinations necessary to drive the waveform generator’s outputs high or low or to connect them to the WG_EVEN or WG_ODD signal. Note that PHx.2 is always set to select the waveform-generator signal function (clearing PHx.2 selects the general-purpose I/O port function). The “Output Polarities” column shows the output polarities. The drawings show a duty cycle of about 15%, and for these cases, the high portion of the waveforms increases as dead time increases.

,

Table 9-5. Output Configuration

PHx.2

PHx.1

PHx.0

Output Values

 

 

 

 

 

Output Polarities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WGx

WGx#

 

 

 

WGx

 

 

 

WGx#

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

0

0

Low

Low

 

 

 

Always Low

 

 

 

Always Low

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

0

1

Low

WG_EVEN#

 

 

 

Always Low

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

1

0

WG_ODD

Low

 

 

 

 

 

 

 

 

 

 

 

 

Always Low

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

1

1

WG_ODD

WG_EVEN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NOTE:

This table assumes active-high outputs (OP1=OP0=1).

 

 

 

 

 

 

 

 

9-12

Page 211
Image 211
Intel 8XC196MH, 8XC196MD, 8XC196MC manual Programming the Waveform Generator, Configuring the Outputs, Output Configuration