Microchip Technology dsPIC30F - Timer Variants

© 2004 Microchip Technology Inc. DS70059C-page 12-3
Section 12. Timers
Timers
12
12.2 Timer Variants
All 16-bit timers available on the dsPIC30F devices are functionally identical with certain
exceptions. The 16-bit timers are classified into three functional types; Type A timers, Type B
timers and Type C timers.
12.2.1 Type A Timer
At least one Type A timer is available on most dsPIC30F devices. For most dsPIC30F devices,
Timer1 is a Type A timer. A Type A timer has the following unique features over other types:
• can be operated from the device Low Power 32 kHz Oscillator
• can be operated in an Asynchronous mode from an external clock source
In particular, the unique features of a Type A timer allow it to be used for Real-Time Clock (RTC)
applications. A block diagram of the Type A timer is shown in Figure 12-1.
Figure 12-1: Type A Timer Block Diagram
Note: Please refer to the device data sheet for the available timers and the type of each.
TON
Sync
SOSCI
SOSCO
PRx
TxIF
Equal
Comparator x 16
TMRx
Reset
Note 1: Refer to Section 7. “Oscillator” for information on enabling the LP Oscillator.
LPOSCEN
Event Flag
(Note 1)
1
0
TSYNC
Q
Q
D
CK
TGATE
TCKPS<1:0>
Prescaler
1, 8, 64, 256
2
TGATE
T
CY
1
0
TCS
1 X
0 1
TGATE
0 0
Gate
Sync