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Time-Base (TB) Submodule

2.2.2 Controlling and Monitoring the Time-base Submodule

Table 2-2shows the registers used to control and monitor the time-base submodule.

Table 2-2. Time-Base Submodule Registers

Register

Address offset

Shadowed

Description

TBCTL

0x0000

No

Time-Base Control Register

TBSTS

0x0001

No

Time-Base Status Register

TBPHSHR

0x0002

No

HRPWM extension Phase Register (1)

TBPHS

0x0003

No

Time-Base Phase Register

TBCTR

0x0004

No

Time-Base Counter Register

TBPRD

0x0005

Yes

Time-Base Period Register

(1)This register is available only on ePWM instances that include the high-resolution extension (HRPWM). On ePWM modules that do not include the HRPWM, this location is reserved. This register is described in the TMS320x28xx, 28xxx High-Resolution Pulse Width Modulator (HRPWM) Reference Guide (SPRU924). See the device specific data manual to determine which ePWM instances include this feature.

The block diagram in Figure 2-2shows the critical signals and registers of the time-base submodule. Table 2-3provides descriptions of the key signals associated with the time-base submodule.

Figure 2-2. Time-Base Submodule Signals and Registers

TBPRD

Period￿Shadow

TBPRD

Period￿Active

 

 

16

 

TBCTR[15:0]

 

 

 

 

16

 

CTR￿=￿Zero

 

Counter

Reset

 

Zero

CTR_dir

Mode

Dir

UP/DOWN

 

 

 

CTR_max

Max

 

Load

 

 

TBCLK

clk

 

 

 

 

 

 

 

TBCTR

 

 

Counter￿Active￿Reg

 

 

16

 

TBPHS

Phase￿Active￿Reg

SYSCLKOUT Clock TBCLK Prescale

TBCTL[HSPCLKDIV]

TBCTL[CLKDIV]

TBCTL[PRDLD]

 

 

 

TBCTL[SWFSYNC]

 

 

CTR￿=￿PRD

 

 

 

 

 

 

EPWMxSYNCI

TBCTL[CTRMODE]

 

 

 

 

CTR￿=￿Zero

Sync

EPWMxSYNCO

 

 

 

CTR￿=￿CMPB Out

TBCTL[PHSEN]

 

 

Select

 

 

Disable

 

 

 

 

 

X

 

 

 

TBCTL[SYNCOSEL]

24

ePWM Submodules

SPRU791D–November 2004–Revised October 2007

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Texas Instruments TMS320x28xx, 28xxx Controlling and Monitoring the Time-base Submodule, Time-Base Submodule Registers