Registers
351
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Programmable Real-Time Unit Subsystem (PRUSS)
Table 13-34. CONTROL Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
14-9
RESERVED
R
0
8
SINGLESTE
P
R/W
0
Single Step Enable: This bit controls whether or not the PRU will only
execute a single instruction when enabled.
0 = PRU will free run when enabled
1 = PRU will execute a single instruction and then the pru_enable bit will be
cleared. Note that this bit does not actually enable the PRU, it only sets the
policy for how much code will be run after the PRU is enabled. The
pru_enable bit must be explicitly asserted. It is legal to initialize both the
single_step and pru_enable bits simultaneously. (Two independent writes are
not required to cause the stated functionality)
7-4
RESERVED
R
0
3
COUNTENA
BLE
R/W
0
PRU Cycle Counter Enable: Enables PRU cycle counters
0 = Counters not enabled
1 = Counters enabled
2
SLEEPING
R/W
0
PRU Sleep Indicator: This bit indicates whether or not the PRU is currently
asleep.
0 = PRU is not asleep
1 = PRU is asleep If this bit is written to a 0, the PRU will be forced to power
up from sleep mode.
1
ENABLE
R/W
0
Processor Enable: This bit controls whether or not the PRU is allowed to
fetch new instructions.
0 = PRU is disabled
1 = PRU is enabled If this bit is de-asserted while the PRU is currently
running and has completed the initial cycle of a multi-cycle instruction
(LBxO,SBxO,SCAN, etc.), the current instruction will be allowed to complete
before the PRU pauses execution. Otherwise, the PRU will halt immediately.
Because of the unpredictability/timing sensitivity of the instruction execution
loop, this bit is not a reliable indication of whether or not the PRU is currently
running. The pru_state bit should be consulted for an absolute indication of
the run state of the core. When the PRU is halted, it’s internal state remains
coherent therefore this bit can be reasserted without issuing a software reset
and the PRU will resume processing exactly where it left off in the instruction
stream.
0
SOFTRESET
R
0
→
1
Soft Reset: When this bit is cleared, the PRU will be reset. This bit is set
back to 1 on the next cycle after it has been cleared.