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Time-Base Submodule Registers
Figure 4-4. Time-Base Control Register (TBCTL)
15 14 13 12 10 9 8
FREE, SOFT PHSDIR CLKDIV HSPCLKDIV
R/W-0 R/W-0 R/W-0 R/W-0,0,1
7 6 5 4 3 2 1 0
HSPCLKDIV SWFSYNC SYNCOSEL PRDLD PHSEN CTRMODE
R/W-0,0,1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-11
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 4-4. Time-Base Control Register (TBCTL) Field Descriptions
Bit Field Value Description
15:14 FREE, SOFT Emulation Mode Bits. These bits select the behavior of the ePWM time-base counter during
emulation events:
00 Stop after the next time-base counter increment or decrement
01 Stop when counter completes a whole cycle:
Up-count mode: stop when the time-base counter = period (TBCTR = TBPRD)
Down-count mode: stop when the time-base counter = 0x0000 (TBCTR = 0x0000)
Up-down-count mode: stop when the time-base counter = 0x0000 (TBCTR = 0x0000)
1X Free run
13 PHSDIR Phase Direction Bit.
This bit is only used when the time-base counter is configured in the up-down-count mode. The
PHSDIR bit indicates the direction the time-base counter (TBCTR) will count after a synchronization
event occurs and a new phase value is loaded from the phase (TBPHS) register. This is
irrespective of the direction of the counter before the synchronization event..
In the up-count and down-count modes this bit is ignored.
0 Count down after the synchronization event.
1 Count up after the synchronization event.
12:10 CLKDIV Time-base Clock Prescale Bits
These bits determine part of the time-base clock prescale value.
TBCLK = SYSCLKOUT / (HSPCLKDIV × CLKDIV)
000 /1 (default on reset)
001 /2
010 /4
011 /8
100 /16
101 /32
110 /64
111 /128
9:7 HSPCLKDIV High Speed Time-base Clock Prescale Bits
These bits determine part of the time-base clock prescale value.
TBCLK = SYSCLKOUT / (HSPCLKDIV × CLKDIV)
This divisor emulates the HSPCLK in the TMS320x281x system as used on the Event Manager
(EV) peripheral.
000 /1
001 /2 (default on reset)
010 /4
011 /6
100 /8
101 /10
110 /12
111 /14
SPRU791D November 2004 Revised October 2007 Registers 95
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