DSPIC30F4013 Microchip Technology Inc., DSPIC30F4013 Datasheet - Page 66

• Manufacturer Part Number: DSPIC30F4013
• Description: Dspic30f3014/4013 High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

dsPIC30F3014/4013
9.1
The 16-bit timer can be placed in the Gated Time Accu-
mulation mode. This mode allows the internal T
increment the respective timer when the gate input sig-
nal (T1CK pin) is asserted high. Control bit, TGATE
(T1CON<6>), must be set to enable this mode. The
timer must be enabled (TON = 1) and the timer clock
source set to internal (TCS = 0).
When the CPU goes into the Idle mode, the timer stops
incrementing unless TSIDL = 0. If TSIDL = 1, the timer
resumes the incrementing sequence upon termination
of the CPU Idle mode.
9.2
The input clock (F
Timer has a prescale option of 1:1, 1:8, 1:64 and 1:256,
selected by control bits, TCKPS<1:0> (T1CON<5:4>).
The prescaler counter is cleared when any of the
following occurs:
• a write to the TMR1 register
• a write to the T1CON register
• device Reset, such as POR and BOR
However, if the timer is disabled (TON = 0), then the
timer prescaler cannot be reset since the prescaler
clock is halted.
TMR1 is not cleared when T1CON is written. It is
cleared by writing to the TMR1 register.
9.3
During CPU Sleep mode, the timer operates if:
• The timer module is enabled (TON = 1) and
• The timer clock source is selected as external
• The TSYNC bit (T1CON<2>) is asserted to a logic
When all three conditions are true, the timer continues
to count up to the Period register and is reset to
0x0000.
When a match between the timer and the Period
register occurs, an interrupt can be generated if the
respective timer interrupt enable bit is asserted.
DS70138E-page 64
(TCS = 1) and
‘0’ which defines the external clock source as
asynchronous.
Timer Gate Operation
Timer Prescaler
Timer Operation During Sleep
Mode
OSC
/4 or external clock) to the 16-bit
CY
to
9.4
The 16-bit timer has the ability to generate an interrupt-
on-period match. When the timer count matches the
Period register, the T1IF bit is asserted and an interrupt
is generated, if enabled. The T1IF bit must be cleared in
software. The timer interrupt flag, T1IF, is located in the
IFS0 Control register in the interrupt controller.
When the Gated Time Accumulation mode is enabled,
an interrupt is also generated on the falling edge of the
gate signal (at the end of the accumulation cycle).
Enabling an interrupt is accomplished via the respec-
tive timer interrupt enable bit, T1IE. The timer interrupt
enable bit is located in the IEC0 Control register in the
interrupt controller.
9.5
Timer1, when operating in Real-Time Clock (RTC)
mode, provides time of day and event time-stamping
capabilities. Key operational features of the RTC are:
• Operation from 32 kHz LP oscillator
• 8-bit prescaler
• Low power
• Real-Time Clock interrupts
These operating modes are determined by setting the
appropriate bit(s) in the T1CON Control register.
FIGURE 9-2:
C1 = C2 = 18 pF; R = 100K
C1
C2
Timer Interrupt
Real-Time Clock
32.768 kHz
XTAL
R
RECOMMENDED
COMPONENTS FOR
TIMER1 LP OSCILLATOR
RTC
© 2007 Microchip Technology Inc.
SOSCI
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