TMS320F2808, TMS320F2806
TMS320F2801, UCD9501
Digital Signal Processors
www.ti.com
SPRS230F–OCTOBER 2003–REVISED SEPTEMBER 2005
Table 6-17. STANDBY Mode Switching Characteristics
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Delay time, IDLE instruction ex-
ecuted to XCLKOUT low
td(IDLE-XCOL)
32tc(SCO)
45tc(SCO)
cycles
Delay time, external wake signal
to program execution resume(1)
cycles
cycles
Without input qualifier
With input qualifier
Without input qualifier
With input qualifier
100tc(SCO)
100tc(SCO) + tw(WAKE-INT)
1125tc(SCO)
•
Wake up from flash
–
Flash module in active
state
td(WAKE-STBY)
•
Wake up from flash
cycles
cycles
–
Flash module in sleep
state
1125tc(SCO) + tw(WAKE-INT)
Without input qualifier
With input qualifier
100tc(SCO)
•
Wake up from SARAM
100tc(SCO) + tw(WAKE-INT)
(1) This is the time taken to begin execution of the instruction that immediately follows the IDLE instruction. execution of an ISR (triggered
by the wake up signal) involves additional latency.
(A)
(C)
(E)
(D)
(B)
(F)
Device
Status
STANDBY
STANDBY
Normal Execution
Flushing Pipeline
Wake−up
Signal
t
w(WAKE-INT)
t
d(WAKE-STBY)
X1/X2 or
X1 or
XCLKIN
XCLKOUT
t
d(IDLE−XCOL)
A. IDLE instruction is executed to put the device into STANDBY mode.
B. The PLL block responds to the STANDBY signal. SYSCLKOUT is held for approximately 32 cycles before being
turned off. This 32-cycle delay enables the CPU pipe and any other pending operations to flush properly.
C. Clock to the peripherals are turned off. However, the PLL and watchdog are not shut down. The device is now in
STANDBY mode.
D. The external wake-up signal is driven active.
E. After a latency period, the STANDBY mode is exited.
F. Normal execution resumes. The device will respond to the interrupt (if enabled).
Figure 6-12. STANDBY Entry and Exit Timing Diagram
Electrical Specifications
97
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