Texas Instruments TMS320F28015 Low-Power Modes Block, LPMCR010, Oscclk Clkin Sysclkout, Exit

TMS320F2809, TMS320F2808, TMS320F2806

TMS320F2802, TMS320F2801, TMS320C2802

TMS320C2801, TMS320F28016, TMS320F28015

SPRS230L –OCTOBER 2003 –REVISED DECEMBER 2009 www.ti.com

3.7Low-Power Modes Block

The low-power modes on the 280x are similar to the 240x devices. Table 3-18summarizes the various modes.

Table 3-18. Low-Power Modes

MODE	LPMCR0(1:0)	OSCCLK	CLKIN	SYSCLKOUT		EXIT (1)
						Watchdog interrupt, any enabled
IDLE	00	On	On	On(2)	XRS,
					interrupt, XNMI
		On				Watchdog interrupt, GPIO Port A
STANDBY	01		Off	Off	XRS,
		(watchdog still running)			signal, debugger(3), XNMI
		Off
					XRS, GPIO Port A signal, XNMI,
HALT	1X	(oscillator and PLL turned off,	Off	Off
					debugger(3)
		watchdog not functional)

(1)The Exit column lists which signals or under what conditions the low power mode will be exited. A low signal, on any of the signals, will exit the low power condition. This signal must be kept low long enough for an interrupt to be recognized by the device. Otherwise the IDLE mode will not be exited and the device will go back into the indicated low power mode.

(2)The IDLE mode on the C28x behaves differently than on the 24x/240x. On the C28x, the clock output from the CPU (SYSCLKOUT) is still functional while on the 24x/240x the clock is turned off.

(3)On the C28x, the JTAG port can still function even if the CPU clock (CLKIN) is turned off.

The various low-power modes operate as follows:

IDLE Mode: This mode is exited by any enabled interrupt or an XNMI that is recognized by the processor. The LPM block performs no tasks during this mode as long as the LPMCR0(LPM) bits are set to 0,0.

STANDBY Mode:	Any GPIO port A signal (GPIO[31:0]) can wake the device from STANDBY
	mode. The user must select which signal(s) will wake the device in the
	GPIOLPMSEL register. The selected signal(s) are also qualified by the
	OSCCLK before waking the device. The number of OSCCLKs is specified in
	the LPMCR0 register.
HALT Mode:	Only the		and any GPIO port A signal (GPIO[31:0]) can wake the
		XRS
	device from HALT mode. The user selects the signal in the GPIOLPMSEL
	register.

NOTE

The low-power modes do not affect the state of the output pins (PWM pins included). They will be in whatever state the code left them in when the IDLE instruction was executed. See the TMS320x280x, 2801x, 2804x DSP System Control and Interrupts Reference Guide (literature number SPRU712) for more details.

52 Functional Overview Copyright © 2003–2009, Texas Instruments Incorporated

Submit Documentation Feedback

Product Folder Link(s): TMS320F2809 TMS320F2808 TMS320F2806 TMS320F2802 TMS320F2801 TMS320C2802

TMS320C2801 TMS320F28016 TMS320F28015