SDA55XX Datasheet, PDF (126/230 Pages) Infineon Technologies AG – Preliminary & Confidential

SDA 55xx
Preliminary & Confidential
Capture reload timer
13.3.3 Run
When counter is started (RUN), 16 bit reload value is automatically loaded in the 16 bit
counter. (Note REL bit is irrelevant in case of RUN function). Setting run bit resets the
FIRST and OV bit.
All the control bits PR, PLG, REL, RUN, RISE, FALL, SEL, Start, Int_Src, SD can be
changed anytime during the operation, these changes take immediate effect there is no
protected mode when counter is running.
13.3.4 Overflow
In case no capture event occurs, counter keeps on counting till it overflows from FFFF_h
to 0000_h at this transition OV bit is set. After the overflow counter keeps on counting.
Overflow does not reload the reload value. Note that OV bit is set by counter and can be
reset by software.
13.3.5 Modes
There are three different modes in which counter can be used.
• Normal Capture mode
• Polling mode
• Capture mode with spike suppression at the start of a telegram
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For each mode selection it is recomended to reset the RUN bit (if it is not already at 0),
set the appropriate mode bit and then start the counter by setting the RUN bit.
For each of the capture mode the event is captured based on the CRTCON0(RiISE) and
CRTCON0(FALL).
13.3.6 Normal Capture mode
Normal capture mode is started by setting the RUN bit( 0 --> 1) and PLG = 0, start =0 .
Setting RUN bit will reload the counter with reload value and reset the overflow bit and
counter will start to count.
Upon event on the selected port pin, contents of the counter are copied to the capture
registers CRT_caph and CRT_capl.
Semiconductor Group
126
User’s Manual July 99