Datasheet

© 2006 Microchip Technology Inc. Preliminary DS70178C-page 87
dsPIC30F1010/202X
8.0 TIMER1 MODULE
This section describes the 16-bit General Purpose
Timer1 module and associated operational modes.
Figure 8-1 depicts the simplified block diagram of the
16-bit Timer1 Module.
The following sections provide a detailed description of
the operational modes of the timers, including setup
and control registers along with associated block
diagrams.
The Timer1 module is a 16-bit timer which can serve as
the time counter for the real-time clock, or operate as a
free running interval timer/counter. The 16-bit timer has
the following modes:
• 16-bit Timer
• 16-bit Synchronous Counter
• 16-bit Asynchronous Counter
Further, the following operational characteristics are
supported:
• Timer gate operation
• Selectable prescaler settings
• Timer operation during CPU Idle and Sleep
modes
• Interrupt on 16-bit period register match or falling
edge of external gate signal
These operating modes are determined by setting the
appropriate bit(s) in the 16-bit SFR, T1CON. Figure 8-1
presents a block diagram of the 16-bit timer module.
16-bit Timer Mode: In the 16-bit Timer mode, the timer
increments on every instruction cycle up to a match
value, preloaded into the period register PR1, then
resets to 0 and continues to count.
When the CPU goes into the Idle mode, the timer will
stop incrementing, unless the TSIDL (T1CON<13>)
bit = 0. If TSIDL = 1, the timer module logic will resume
the incrementing sequence upon termination of the
CPU Idle mode.
16-bit Synchronous Counter Mode: In the 16-bit
Synchronous Counter mode, the timer increments on
the rising edge of the applied external clock signal,
which is synchronized with the internal phase clocks.
The timer counts up to a match value preloaded in PR1,
then resets to 0 and continues.
When the CPU goes into the Idle mode, the timer will
stop incrementing, unless the respective TSIDL bit = 0.
If TSIDL = 1, the timer module logic will resume the
incrementing sequence upon termination of the CPU
Idle mode.
16-bit Asynchronous Counter Mode: In the 16-bit
Asynchronous Counter mode, the timer increments on
every rising edge of the applied external clock signal.
The timer counts up to a match value preloaded in PR1,
then resets to ‘0’ and continues.
When the timer is configured for the Asynchronous mode
of operation and the CPU goes into the Idle mode, the
timer will stop incrementing if TSIDL = 1.
Note: This data sheet summarizes features of this group
of dsPIC30F devices and is not intended to be a complete
reference source. For more information on the CPU,
peripherals, register descriptions and general device
functionality, refer to the “dsPIC30F Family Reference
Manual” (DS70046).
Note: Timer1 is a ‘Type A’ timer. Please refer to
the specifications for a Type A timer in
Section 21.0 “Electrical Characteris-
tics” of this document.