Pepper Computer Modular Computers RS232 사용자 설명서

SMART I/O User’s Manual

March 12, 1996

©1996 PEP Modular Computers GmbH

Page 2 - 36

Chapter 2  SMART-BASE

: With this call the counter preload register can be

  set. The syntax is as follows :

<RetVar> := OPERATE(<iovar>, O_PRELOAD, <prevar>);

  where the 

<iovar>

 is typically t_in and

  

<prevar>

 is the value for the preload register

  which lies between 1 and 0xFFFFFF.

: This function starts the counter counting-down.

  When the counter reaches zero, it rolls over to the

  maximum value of 0xFFFFFF on the following

  clock pulse and starts afresh. The syntax is as

  follows :

<RetVar> := OPERATE(<iovar>,O_START_CNTDWN,<prevar>);

  where the 

<iovar>

 is a variable attached to the

  Timer I/O (typically t_in) and 

<prevar>

 may be

  one of 

OA_PITCLOCK

 for selection of the

  6 MHz/32 clock input or 

OA_TIN

 for selection of

  t_in inputs.