Timer Preload Register (Tpr) - Motorola DSP56156 Manual

the timer gets enabled (TE=1). In that case, the value stored or written in the preload reg-
ister will be loaded into the count register on the next event after it reaches zero, unless
another write to the count register is performed in between. Refer to Section 7.8, Func-
tional Description of the Timer , for more details.
The count register is initialized to zero on hardware RESET and software reset (RESET
instruction).
ES=0
Fosc
/2
TIN
ES=1
INV
Figure 7-1 16-bit Timer General Block Diagram
7.4

TIMER PRELOAD REGISTER (TPR)

The preload register is a 16-bit read/write register which typically contains the value to be
reloaded inside the count register when the timer is enabled and when the timer count reg-
ister (TCTR) has been decremented to zero.
If the timer is enabled (TE=1) when the user program writes a new value inside the pre-
load register (TPR), this new value is transferred to the count register the next time the
count register is loaded (after it reaches zero), unless a direct write to the count register
is performed while the TCTR is zero.
7 - 4

TIMER PRELOAD REGISTER (TPR)

GDB
DC0-DC7
8-bit decrement
register
TCPR
16-bit
compare register
16-BIT TIMER AND EVENT COUNTER
16-bit
TPR
16-bit
preload register
TCTR
dec
16-bit
count register
=
Compare Overflow
Interrupt Interrupt
TO2-TO0
TOUT
MOTOROLA