INFORMATION ADVANCE

TMS320C6678

Multicore Fixed and Floating-Point Digital Signal Processor

SPRS691—November 2010

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7.23 Timers

The timers can be used to: time events, count events, generate pulses, interrupt the CPU, and send synchronization events to the EDMA3 channel controller.

7.23.1 Timers Device-Specific Information

The TMS320C6678 device has eight 64-bit timers in total. Of which Timer0 through Timer3 are dedicated to each of the four CorePacs as a watchdog timer and can also be used as general-purpose timers. Each of other 4 timers can also be configured as a general-purpose timer only, with each timer programmed as a 64-bit timer or as two separate 32-bit timers.

When operating in 64-bit mode, the timer counts either VBUS clock cycles or input (TINPLx) pulses (rising edge) and generates an output pulse/waveform (TOUTLx) plus an internal event (TINTLx) on a software-programmable period.

When operating in 32-bit mode, the timer is split into two independent 32-bit timers. Each timer is made up of two 32-bit counters: a high counter and a low counter. The timer pins, TINPLx and TOUTLx are connected to the low counter. The timer pins, TINPHx and TOUTHx are connected to the high counter.

When operating in Watchdog mode, the timer counts down to zero and generates an event. It is a requirement that software writes to the timer before the count expires, after which the count begins again. If the count ever reaches zero, the timer event output is asserted. Reset initiated by a watch dog timer can be set by programming ‘‘Reset Type Status Register (RSTYPE)’’ on page 221 and the type of reset initiated can set by programming ‘‘Reset Configuration Register (RSTCFG)’’ on page 223. For more information, see the 64-bit Timer (Timer 64) for KeyStone Devices User Guide (literature number SPRUGV5).

7.23.2 Timers Electrical Data/Timing

The tables and figures below describe the timing requirements and switching characteristics of Timer0 through Timer7 peripherals.

Table 7-93

Timer Input Timing Requirements

 

 

 

(see Figure 7-58)

 

 

 

 

 

 

 

 

 

 

No.

 

 

Min

Max

Unit

1

tw(TINPH)

Pulse duration, high

12C

 

ns

2

tw(TINPL)

Pulse duration, low

12C

 

ns

End of Table 7-93

 

 

 

 

 

 

 

 

 

Table 7-94

Timer Output Switching Characteristics

 

 

 

(see Figure 7-58)

 

 

 

 

 

 

 

 

 

 

No.

 

Parameter

Min

Max

Unit

3

tw(TOUTH)

Pulse duration, high

12C - 3

 

ns

4

tw(TOUTL)

Pulse duration, low

12C - 3

 

ns

End of Table 7-94

 

 

 

 

 

 

 

 

 

248 TMS320C6678 Peripheral Information and Electrical Specifications

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