WAVEFORM GENERATOR

9.4.2Controlling the Protection Circuitry and EXTINT Interrupt Generation

The protection register (Figure 9-9) controls the protection circuitry and EXTINT interrupt re- quests.

WG_PROTECT

Address:

1FCEH

 

Reset State (MC, MD)

F0H

 

Reset State (MH):

E0H

The waveform protection (WG_PROTECT) register enables and disables the outputs and the protection circuitry. It also selects either level-sensitive or edge-triggered EXTINT interrupts, and selects which level or edge will generate an EXTINT interrupt request.

8XC196MC, MD

8XC196MH

7

7

 

 

 

 

 

 

 

PT

 

 

 

 

0

ES

IT

DP

EO

 

 

 

0

 

 

 

 

ES

IT

DP

EO

 

 

 

 

Bit

Bit

 

 

 

Function

Number

Mnemonic

 

 

 

 

 

 

 

 

 

 

7:5

Reserved; for compatibility with future devices, write zeros to these bits.

 

 

 

 

6†

PT

Protection Type

 

 

 

This bit selects the method used for disabling the outputs.

 

 

0

= inactive states

 

 

1

= weak pull-ups

 

 

 

3:2

ES

Enable Sampling and Interrupt Type

 

IT

The ES bit selects whether the protection circuitry samples the EXTINT

 

 

 

 

signal level or detects a signal transition (edge), while the IT bit controls

 

 

which value of the edge or level triggers an interrupt request. The

 

 

possible combinations are as follows.

 

 

ES

IT

Event

 

 

0

 

0

falling edge

 

 

0

 

1

rising edge

 

 

1

 

0

low level

 

 

1

 

1

high level

 

 

 

1

DP

Disable Protection

 

 

This bit enables and disables the protection circuitry.

 

 

0

= enable protection

 

 

1

= disable protection

 

 

 

 

0

EO

Enable Outputs

 

 

 

This bit enables and disables the outputs.

 

 

0

= disable outputs

 

 

1

= enable outputs

 

 

 

 

 

 

On the 8XC196MC, MD devices, this bit is reserved. For compatibility with future devices, always write as zero.

Figure 9-9. Waveform Generator Protection (WG_PROTECT) Register

9-15

Page 214
Image 214
Intel 8XC196MD manual Wgprotect, F0H, E0H, 8XC196MC, MD 8XC196MH Bit Function Number Mnemonic, Event