![](http://datasheet.mmic.net.cn/360000/TMS320F2810GHHMEP_datasheet_16673387/TMS320F2810GHHMEP_108.png)
Electrical Specifications
108
March 2004 Revised October 2004
SGUS051A
6.17
Event Manager Interface
6.17.1
PWM Timing
PWM refers to all PWM outputs on EVA and EVB.
Table 613. PWM Switching Characteristics
PARAMETER
TEST CONDITIONS
MIN
MAX
UNIT
tw(PWM)§
td(PWM)XCO
See the GPIO output timing for fall/rise times for PWM pins.
PWM pin toggling frequency is limited by the GPIO output buffer switching frequency (20 MHz).
§PWM outputs may be 100%, 0%, or increments of tc(HCO) with respect to the PWM period.
Table 614. Timer and Capture Unit Timing Requirements
#
Pulse duration, PWMx output high/low
25
ns
Delay time, XCLKOUT high to PWMx output switching
XCLKOUT = SYSCLKOUT/4
10
ns
MIN
MAX
UNIT
tw(TDIR)
Pulse duration, TDIRx low/high
Without input qualifier
2 * tc(SCO)
1 * tc(SCO) + IQT||
2 * tc(SCO)
1 * tc(SCO) + IQT||
40
cycles
With input qualifier
tw(CAP)
Pulse duration, CAPx input low/high
Without input qualifier
cycles
With input qualifier
tw(TCLKINL)
tw(TCLKINH)
tc(TCLKIN)
The QUALPRD bit field value can range from 0 (no qualification) through 0xFF (510 SYSCLKOUT cycles). The qualification sampling period is
2n SYSCLKOUT cycles, where “n” is the value stored in the QUALPRD bit field. As an example, when QUALPRD = 1, the qualification sampling
period is 1 x 2 = 2 SYSCLKOUT cycles (i.e., the input is sampled every 2 SYSCLKOUT cycles). Six such samples will be taken over five sampling
windows, each window being 2n SYSCLKOUT cycles. For QUALPRD = 1, the minimum width that is needed is 5 x 2 = 10 SYSCLKOUT cycles.
However, since the external signal is driven asynchronously, a 11-SYSCLKOUT-wide pulse ensures reliable recognition.
#Maximum input frequency to the QEP = min[HSPCLK/2, 20 MHz]
||Input Qualification Time (IQT) = [5 x QUALPRD x 2] * tc(SCO)
Pulse duration, TCLKINx low as a percentage of TCLKINx cycle time
60
%
Pulse duration, TCLKINx high as a percentage of TCLKINx cycle time
40
60
%
Cycle time, TCLKINx
4 * tc(HCO)
ns
tw(PWM)
td(PWM)XCO
PWMx
XCLKOUT
XCLKOUT = SYSCLKOUT
Figure 616. PWM Output Timing
XCLKOUT
tw(TDIR)
TDIRx
XCLKOUT = SYSCLKOUT
Figure 617. TDIRx Timing