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

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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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