STANDARD TIMER (STIM)
10.2 STANDARD TIMER (STIM)
10.2.1 Introduction
the prescaler can be driven either by an internal
clock equal to INTCLK divided by 4, or by
CLOCK2/1024 derived directly from the external
oscillator, thus providing a stable time reference
independent from the PLL programming (refer to
Figure 90).
The Standard Timer includes a programmable 16-
bit down counter and an associated 8-bit prescaler
with Single and Continuous counting modes capa-
bility. The Standard Timer uses an output
(STOUT) pin. This pin may be independent pin or
connected as Alternate Function of an I/O port bit.
The Standard Timer End Of Count condition is
able to generate an interrupt which is connected to
one of the external interrupt channels.
STOUT can be used to generate a Square Wave
or Pulse Width Modulated signal.
The End of Count condition is defined as the
Counter Underflow, whenever 00h is reached.
The Standard Timer is composed of a 16-bit down
counter with an 8-bit prescaler. The input clock to
Figure 90. Standard Timer Block Diagram
n
INMD1 INMD2
INEN
INPUT
&
STH,STL
16-BIT
DOWNCOUNTER
STP
CLOCK CONTROL LOGIC
MUX
8-BIT PRESCALER
STANDARD TIMER
CLOCK
INTCLK/4
END OF
COUNT
CLOCK2/1024
STOUT
OUTMD2
OUTMD1
OUTPUT CONTROL LOGIC
EXTERNAL
INTERRUPT
INTERRUPT
INTS
CONTROL LOGIC
INTERRUPT REQUEST
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STMICROELECTRONICS [ ST ]
