ꢀ ꢁꢂ ꢃ ꢄ ꢅ ꢆꢇ ꢄ ꢈꢈ ꢉ ꢀ ꢁꢂ ꢃ ꢄꢅ ꢆꢇ ꢄꢈꢈꢊ
ꢋ ꢌꢍ ꢎꢏꢐꢑꢒ ꢌ ꢓꢀ ꢏꢌ ꢔꢌ ꢀꢕꢖ ꢂꢌ ꢔ ꢓꢕꢖ ꢑꢗ ꢒ ꢆꢎ ꢂ ꢂꢒ ꢗ ꢂ
SPRS073L − AUGUST 1998 − REVISED JUNE 2005
31
16
15
14
13
12
11
PD2
R/W-0
10
9
8
0
Enable or
Non-Enabled
Interrupt Wake
Enabled
Interrupt Wake
Reserved
R/W-0
PD3
PD1
R/W-0
R/W-0
R/W-0
R/W-0
7
Legend: R/W−x = Read/write reset value
NOTE: The shadowed bits are not part of the power-down logic discussion and therefore are not covered here. For information on these other
bit fields in the CSR register, see the TMS320C6000 CPU and Instruction Set Reference Guide (literature number SPRU189).
Figure 8. PWRD Field of the CSR Register
A delay of up to nine clock cycles may occur after the instruction that sets the PWRD bits in the CSR before the
PD mode takes effect. As best practice, NOPs should be padded after the PWRD bits are set in the CSR to account
for this delay.
If PD1 mode is terminated by a non-enabled interrupt, the program execution returns to the instruction where
PD1 took effect. If PD1 mode is terminated by an enabled interrupt, the interrupt service routine with be executed
first, then the program execution returns to the instruction where PD1 took effect. In the case with an enabled
interrupt, the GIE bit in the CSR and the NMIE bit in the interrupt enable register (IER) must also be set in order
for the interrupt service routine to execute; otherwise, execution returns to the instruction where PD1 took effect
upon PD1 mode termination by an enabled interrupt.
PD2 and PD3 modes can only be aborted by device reset. Table 19 summarizes all the power-down modes.
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